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Indian Agricultural
Research Institute, New Delhi.

IS8o?>A- t$Sc^

I. A.R.I.6.

MGIPC — SI — C AR/ot— 7-7-54— 10,000.

THE

Agricultural Journal

British Guiana

DEPARTMENT OF AGRICULTURE
GEORGETOWN
BRITISH GUIANA.

Vol. IX, No. i.

March, 1938.

The

Agricultural Journal

British Guiana

IS803

» •

PUBLISHED BY

THE DEPARTMENT OF AGRICULTURE,

GEORGETOWN BRITISH GUIAW

Price

»■

• a

6d.

DEPARTMENT OF AGRICULTURE.

ADMINISTRATION

Director of Agriculture ... ... Prof. The Hon. J. Sydney Dash,

B.Sc. (AgriM

Deputy Director ... ... ... F. Burnett, M.C., M.A.

Clerical

Senior Clerk
Registrar of Banks

Class III Clerks

Probationers

Librarian

RESEARCH BRANCH.

Botany and Plant Pathology

Botanist — Plant Pathologist ami Superintend •
ent. Hot anii : Garden*:

E. B. Martyn, B A.. A.I.C.T.A.

T<<h)ttcal A distant :

X. Porsaud

Chemistry

Chemist :

D, W. Duthie. M.A . B.Sc,, rh.D M F.T.C.
A ssistant Chemist :

C. L. C. Bourne

Entomology

Entomologist .

L. D. Clear©, F.R. Ent. S.

Technical Assistant *

C. Will nuns

Rice

Assistant Plant Brtethr:

P. A. Ch:m*Clioong, B.Sc., A.T.C T.A.

Sugar

(In co-operation with the Sugar Producers)
Sugar Agronomist and Plant Bncd/r :

C. H. B. Williams. M.A., A.LC.T.A.. Dip.
Agr. 1

Laboratory Assistants :

H. B. Singh

A, V. Wan-Piug, Dip. Agr.

Statistical Clerk :

J. B. Bourne

Staff.

J. F. Irving. M.C.

W. G. Delph
( A. A. Thorne
< Miss X. Green
( Miss D. M. Terrill
Miss M. Cheong
P. O. Jackson
S. a. Adams
Miss It. Delph

Miss V. Chnn-Choong

LIVESTOCK BRANCH

Veterinary Surgeon .

T. Bone, O.B.E . M.R.C.V.S.

FIELD BRANCH

Agricultural Superintendent s ■

Berbice- .1 D. Gillespie, B.Sc.

Demerara, East— E.M. Peterkin
Demerara, East Bank— H. 1). Huggins,
M.Sc., Dip. Agr.

Demerara. West — E. G. Benson, B.Sc,,
A.I.C.T.A.. Dip. Agr.

Exsequibo A. A. Abraham
A ssistant Agricultural Superintendent .

Berbice -E. M. Morgan
Agricultural Instructors :

Botanic Gardens- — H. A. Eole
Demerara, Eaxf-- j C C. Dowding, F L.S ,
] F.R.H.S.

IW. A. Boveli.

Demerara. East Bank— I. Dewar (acting)
Essequibo — A. W. Sears
Xorth West District — L. E. McKinnon
Agricultural Assistants :

Demerara. East — J. Indrobeharry
Berbice— H. B. France

Sugar

Field Manager (Central Station)

C. Cameron
Field Assistants :

L. A. Forte
B. A. McArthur

METEOROLOGICAL BRANCH

Technical Assistant :

D. D. Blackman

Meteorological Assistant .

J. E, Isaac*

RICE GRADING BRANCH

Grading Inspector :

H. E. H. Gadd

Technical Assistant * :

G. L. Leitch
B. R. Ross

ADVISORY BOARD OF AGRICULTURE

Director of Agriculture, Chairman, ex officio.

Deputy Director ot Agriculture, Vice-Chairman, ex officio.

Hon. Peer Bacchus ... ••• \

Hon. R E. Brassing! on ... ••• 1

Hon. J W Jackson .. ... •• f

Hon. F. J. Seaford, oji.e ... ... ... > Members

Mr. S. Andries ... ... ... ... [

,. R. B, Hunter ... ... )

W. H. Richards ... ... '

SUGAR EXPERIMENT STATIONS COMMITTEE.

Director of Agriculture, Chairman, ex-officio.
Hon. M. B G, Austin
Mr. J. Bee
,, G. M. Eccles
„ J. C. Gibson
.. A. Murison
„ R. E. Rhodes

Georgetown
Pin. Albion
Pin. Blairmont
Pin. Port/Mourant
Pin. Uitvlugt
Pin. Diamond

( Representing
the Sugar
Industry
which main*
tains the
J Stations

CO-OPERATIVE CREDIT BANKS’ BOARD.

Director of Agriculture, Chairman, ex-officio.
Dr. the Hon. J. B. Singh ...

Rev. A. E. Dyett ...

Mr. 0. Farnum
„ J. L. Wills ..

Members

DISTRICT AGRICULTURAL COMMITTEES

Director of Agriculture, Chairman
District Commissioner
Deputy Director of Agriculture
Hon. J. I. dc Aguiar
Hon. E. M. Walcott
Mr. 8. Andries ...

„ M. Ghani ...

„ W. H. Richards
„ J. E. Wills ...

EAST DEMERARA

WEST DEMERARA

Director of Agriculture, Chairman
District Commissioner

Deputy Director of Agriculture ... ]

Hon. J. W Jackson .. ... .. |

Dr. the Hon. J. B. Singh ... ... j

Mr. R. P. Carry 1 ... ... ... i

„ J.C. DaSilva ... ... ...

„ R. B. Hunter
A. Murison ...

,, W Ramdeholl
„ A. Rayman ...

Members

CONTENTS.

(VOL. IX, No. 1.)

EDITORIAL — Grasses

Page

ORIGINAL ARTICLES.

The Use of Vegetation for

Coast Protection ... Geiald 0. Caw ... ... ... 4

Status of the Amazon Fly in

British Guiana, 1937 ... L, D. Clean, F.R. Ent. S. ... ... 12

Plant Legislation in Brit-
ish Guiana and the

Caribbean Colonies ... L. D . Clear e . F.Ii. Enl. S. ... ... 25

SELECTED ARTICLES.

Presidential Address
(Fourth International

Grassland Congress) ... Prof. R. G. Stapledon, C.B.E., J/.A. ... 39

The Boring Points for
Refractometer Tests of

Sugar Cane ... C. Cameron & II. B. Singh ... ... 47

Coffee Quality

• It Ml

...

Bronze-Leaf Wilt Disease
of the Coconut Palm ...

NOTES.

t • • • * «

Rotenone Yielding Plants
of South America

• ■ • • • •

» » *

Surinam and Curacao

<n « * #

i * •

Soil EroBion

» • « • • •

...

Clarification of Sugar
Syrups

» • « * • •

...

... * (51

Legislation ... ...

•

It* 9t«

Contents— Continued .

REVIEW.

Page

The Practical Aspects of Copra Deterioration ... ... ... 63

MEETING OF B.G. BEEKEEPERS’ ASSOCIATION ... ... 04

NEWS ... ... ... ... ’ ... 67

PLANT AND SEED IMPORTATION ... ... ... 69

METEOROLOGICAL DATA ... ... ... ... 70

CURRENT PRICES OF COLONIAL PRODUCE ... ... 7a

ILLUSTRATIONS

Facing

Page

Plate

I.— Fig.

1 — Grasses and Young Courida at Nog Kens

Fig.

2 — Spartina Grass Growing at Kitty foreshore

Plate

II.— Fig.

3 — Various Grasses and Plants growing on

Foreshore. Hope, East Coast, Demerara ...

»»

•» I ig.

1 — Mangrove Trees on Essequibo ("oast

Plate

III.— Fig.

o — Courida trees being rapidly eroded by wave
action at Union, West Coast, Demerara

» I ig*

fi — Holes formed in the Foreshore by tallen
Courida trees and stumps

Plate

IV.— Fig.

7 — Young Mangnrse trees planted behind
a bamboo pallisade

Fig.

8 — Young Mangrove trees planted in front
of earth dam

Plate

V.— Fig.

0 — Sand spit formed at Hidden Fleece, Jan-
uary, 11*33

,. — Fig.

10 — Landward view from Golden Fleece
groyne in January, 1035

Plate

VI.— Fig.

11 — Landward yiew from Golden Fleece
gro\nein September, 1035

„ — Fig.

12 -^Natural Sand, and Shell embankment at
Woodlands, East Coast, Demerara

Plate

VII.— Fig.

13— -Natural Sand embankment at Suddie

Esfeequibo

The

Agricultural Journal of British Guiana.

March, 1938.

EDITORIAL

GRASSES.

Animals depend for a living on the vegetable kingdom, and rely more on
one family in this kingdom than on all of the three hundred other families of
flowering plants combined. The family of such outstanding importance is the
grasses, and there are some who contend that as the path of civilization pro-
gressed its course was directed in no unmistakable manner by the nature of the
grass which grew in a particular region. The distinctive Malay and Chinese
civilization was based on rice, the Ar>an and Semitic civilization was bused on
wheat and barley, primitive African civilizations were based on the sorghums ;
in America there was yet another type of civilization based on maize — a grass
entirely unknown in its wild stage so long has it been cultivated.

In -the grasses are included the cereals — wheat, barley, rye, oats, millet and
sorghum of the Old World, rice and maize of the East and of tho New World.
The culture of cereals dates from time immemorial. Records show that even
in the twelfth century production of these crops was already intimately woven
into social customs and habits ; it appears, for instance, that wheat bread was
associated with the luxury and entertainment of the upper classes. A Latin
poem, published about that time, draws attention to a custom which found
favour with the housewife of those da> s and which doubtless was tho forerunner
of some of our modern university courses in Home Economics : —

“ With common pit we they buy, 7 is said ,

“ .4 single loaf of whenten bread .

“ They /ml if under loth and hey ,

“ And if a guest they chance to sec,

"/They bid the servant go for if —

“ But no one dares to cut a bit /

Rice, it may be mentioned, is considered the world’s greatest crop and forms
the staple diet of more people than any other food. *

In this family too, are the pasture grasses of the world. Primitive man
depended largely on the animals he could kill and was, therefore, vitally associated

‘ AGRICULTURAL JOURNAL OP BRITISH GUIANA.

lit., i.

with grasslands for good grazing fields and food. The position has not changed
greatly in the twentieth century. Elsewhere in this Journal is reprinted the
Presidential Address to the Fourth International Grassland Congress which was
held in Aberystwyth last June. A new orientation which in recent years has
come more and more into prominence is that pasture grasses, being of such far
reaching importance, should receive care and attention equal to that given to
crops. Agricultural communities can no longer afford to permit their pastures
to be untended and indiscriminately grazed. In the words with which Professor
Stapledon closes his address : “ If the people of the world, and to a man, are

indeed to be adequately fed with fresh food of the highest quality, and balanced
in every respect, then the enormous acreage of the world that stands in grass-
land of every character, and of no character at all, must be brought to play
its full part.”

In this same family are to be found the sugar cano, the oil grasses, the
bamboos.

The grasses as a family an*, therefore, of extraordinary importance to the
world in general and in the case of mmy a tropical country their importance is
strikingly emphasised. In British Guiana, for instance, only a relatively narrow
coastal strip has been colonized and agriculturally settled; it is mainly on the
output of this narrow strip that the economic life of the Colony is based. Thus
far there are only two important crops that have been successfully exploited on
the typical coastal soils, and both of them — cane and rice — are grasses. Latest
available figures show that cane products are responsible for 68% of the Colony’s
exports and rice for 7% ; not only are these crops ot importance to the Colony's
well-being but with the present outlook they are an essential for its very
economic existence.

In the account with grasses, the entries are not only on the credit side.
There is no winter in tropical countries to serve as a “ closed season ” and to
interrupt the growth and spread of weeds ; in consequence weed control has
become one of the most important, one of the most expensive of tropical
agricultural operations. The difficulties which are presented in effectively con-
trolling weeds are responsible to a larger extent than is usually appreciated for
the lack of good husbandry to which attention is so frequently drawn in the
case of small-farming in the Tropics. Farmers in this country, as in many others
have fallen into the habit of interchanging the word “ grass” for ” weeds” quite
indiscriminately, for the simple reason that most of the weeds of consequence
are grasses.

Although in British Guiana the fodder and pasture grasses are not playing
the part which it is envisaged that they will one day play when by intelligent and
orderly management a more thriving livestock industry will be supported, the
Livestock Division of the Department is endeavouring to make pasture improve-
ment one of tUj| important features of its work. A visit to the stock farm
paddock at Georffebown will show what can and ought to be done.

BMfOBUL

A direction in which the grass family is of peculiar interest to British
Qniana is in regard to foreshore reclamation and conservation. In an article
elsewhere in this Journal, the Director of Public Works and Sea Defences points
out that the presence of vegetation on the foreshore of British Quiana plays an
important part in reducing erosion. One of the plants found valuable in this con-
nection is a grass, Spartina , which is giving- useful service in foreshore
conservation in this country.

In the subject matter of this Number reference to the grass family is made
in more than one of the articles. For so important a subject such prominence is
deserved.

ORIGINAL ARTICLES.

THE USE OF VEGETATION FOR COAST PROTECTION.

GERALD 0. CASE

Director of Public Works and Sea Defences.

“ When 1 have seen the hungry ocean gain
“ Advantage on the kingdom of the shore
“ And the firm soil win of the watery main
“ Increasing store with loss and lass with store;

“ When I have seen such interchange of state,

“ Or state itself confounded to decay ;

“ Ruin hath taught me thus to ruminate."

Shakespeare, Sonnet LXIV.

Formation op British Guiana CoastiAnds.

The general evidence seems to prove that the present cycle of coast-line
changes in British Guiana was started by an alteration in the relative levels of
land and sea, which cause the formation of a very wide foreshore at low tide.

Every foreshore has a natural inclination of repose and at the commence*
ment of the present cycle of coast-line changes in this country the gradient of
the foreshore was flatter than the natural inclination. In consequence of this
a natural embankment of sand and shell was built up where the waves broke at
high tide. There were numbers of gaps in the naturally formed embankments
through which the rivers discharged into the sea. Behind the naturally formed
embankments was a large area flooded by the sea at every high tide.

The flood tidal current brought in silt and the rivers brought down sand
which was deposited at slack water causing salt marshes to be gradually formed
behind the natural embankments.

In the formation of these salt marshes vegetation played a very important
part in organising and controlling the accretion. Plants which grow on
sheltered areas covered at high tide and dry at low tide slow down currents and
cause material to be deposited Which in the absence of vegetation would be
held iu suspension and moved nmy. Numerous marine animals dwelt among
the plantB and their remains Wd the decay of the plants themselves caused the
formation of the fertile sughr estate lauds in British Guiana.

At the time of the first occupation by Europeans of this country, it is
highly probable that the rate of erosion due to the gradual inland movement of
saud and shelV^embankments was very small and perhaps negligible as they

Plate I.

i «r ] (viissis nid v»ung ( ouj id i it N ng Etn^ E i^t Poi^t, Dcniti ua, taken o\ ci b> sei

owing to » bituli m ^ i w ill

Fij? 2 Spattnui (tiiss giowmg it Kittj Foieslioie Fist (oisi, Dtuiei iru

Plate II.

Fig. 4. — -Mangrove trees on Essecjuibo Coast.

TO! toM 09 dOASf PROTWraJT.

were probably eowred ’with vegetati on* Reclamation of the land behind the
And and shell embankments was gradually dehiered by building dams at right
a&gta* lie the coast-line and putting kokers oil the site of the smaller streams
passing through the embankments or by cutting through the embankments and
building kokers in line with them. It is highly probable that very soon after
the commencement of the reclamation works sea defence troubles commenced as
all naturally formed sand or shell embankments travelled inland unless fixed by
vegetation. History shows that in many countries man did not at first
appreciate the value of vegetation in fixing naturally formed sand embankments
and preventing them gradually moving inland. In consequence the vegetation
was often destroyed, and as the embankments gradually moved inland the
kokers became exposed to the violent wave action as also did the artificial
man-made embankments built to fill in gaps between the natural embankments.
Erosion and gradual disappearance of the naturally formed sand and shell em-
bankments was largely due to artificial causes arising from the empowering of
the marsh land and interference with natural drainage conditions.

On the parts of the coast-line of British Guiana where lands have not been
empoldered, especially between the Pomeroou and Waini rivers, there still exist
long lengths of sand and Bhell embankments clothed by vegetation and here
there are no sea defence problems, but on the East and West Coasts there are
only comparatively few of the natural embankments left.

On the Essequibo coast a natural sand embankment still protects low-lying
land north ot Suddie from inundation by the sea. Such sand embankments are
found on the West Coast of Berbice and on the Corentyno Coast.

It is important to place on record the useful part which vegetation can play
in preventing erosion of naturally formed sand and shell embankments so that
in the future reclamation of any area behind naturally formed embankments,
such as the large area between the Pomeroon and Waini rivers, care may be
taken to preserve existing vegetation and plant more where necessary.

ZONEH OP V BkSliTATION.

The vegetation of the sea-bed, foreshore and on salt marshes may be
divided into zones : —

1. Sea-bed.

2. Foreshore covered by the sea at neap tides (area between high-
water line of neap tides and low-water line of neap tides).

3. Foreshore covered by the sea at spring-tides only (area between
* high-water line of neap tides and high-water line of spring

tides).

4. Salt marshes covered only by the occasional highest spring
tides.

5. Sand embankments above high-water level of ordinary spring

tides,

AGSKStrttWlUt JMBMU9MM 1 1MMII OWMi

‘jft rfc i

Included fa these none* we find various species of . both hydrtiphyt** ana
hallopbytes, -which grow on sand and mud, and -which aoetunulate and fit
material transported by the tides and currente. The decay of these plants isiso
adds to the rising surface. The plants are usually distributed in zones, and
often very gradually pass over into salt-marsh formations. In shallow beds of
seas associations of microphytes and the large algae grow on sand and mud.
The hallophitic communities are divided into those that are psammapbilons,
pelophilous and helophilous, according as the substratum consists respectively of
sand, of mud or of swamp.

Whenever there is a breach in the line of sea defences and the sea dam Is
retired forming a bay to the general line of defence the salt water first kills out
the land grasses and plants and then oourida trees start to grow.

Fig. 1 shews young courida and salt grasses now growing in the bay caused
by retiring the sea dam at Nog Eens owing to the big breach in the sea wall.
The vegetation slows down the tidal current and accretion takes place at a
more rapid rate than it would do in a bay without vegetation. The tendency
is for erosion to take place at headlands and accretion in bays.

Beyond low-water line in Europe and parts of Americb, “eel” grass or sea
grass ( Zostera marina ) often grows on the sea bed and rapidly accumulates sand
and mud, but it is tfot found in British Gniana. When the shore has been raised
to above low-water mark of ordinary spring tides, Spartina grass, Batis and other
plants commence to grow, and when they in their turn have raised the level
to above high-water mark of neap tides, other plants assist in the work of
reclamation up to high-water level of ordinary spring tides.

I do not propose to give any detailed description of the foreshore vegeta-
tion in British Gniana, and would refer interested readers to the article by E. B.
Martyn, published in the Journal of Ecology, Volume XXII, No 1, 1934,
describing the foreshore vegetation eastward of the Kitty groyne.

On the coasts where the shore is of a rocky nature and high tides wash the
base of the cliffs, and also where there is a comparatively smal) horizontal range of
tide, marine vegetation and animal life produce little effect in causing accumu-
lation. Three conditions are necessary for the formation of salt marshes on
tidal foreshores. Firstly, the foreshore must be sheltered from rough seas ;
secondly, there mast be an ample supply of sand and mud brought in by the
tides or carried down by the rivers ; and thirdly, there must be an adequate
number of suitable plants growing on the foreshore.

The algae which grow on the sea-bed are usually attached to stones or
rocks, mid are not of much importance in raising the shore level. There are,
however, a few species having capillary root-like organs which grow in masses
on loose sand or mud. These grow on sandy shores in sheltered bays and
estuaries, where there is a tendency for accumulation to take place. They assist
the process of accretion in several ways. Firstly, the algal growth slows down

Flats III.

Fig. C.— Holes formed in the foreshore by fallen courida trees and stumps.

PLATB IV.

m mm m vwwAfio* ton coast protection. 7

the currents and causes sand and mad to be deposited and collected ; secondly,
the carpet-like covering of seaweed forms a protection to the shore end tends to
prevent erosion daring gales ; thirdly, the decay of the embedded Beaweed in the
gradually rising shore surfaoe forms a humus, the sand being thus manured, and
a soil is formed in course of time in which the higher forms of vegetation can
grow.

On tidal mnddy foreshores in many places various species of flowering
plants (chiefly grasses) grow strongly from high-water to half-tide level, and
form a dense mass (Pigs. 2 and H). As the surface is gradually raised by sediment
deposited by the incoming tide, and in some cases by streams bringing debris worn
from the land, and by accumulation of dead vegetation and shell-bearing animals,
a salt marsh is formed and gradually grows seaward. The ordinary species of plants
which build up salt marshes do not do so above ordinary high spring-tide level
as they require to be covered periodically by the sea in order to flourish. When
salt marshes have grown upwards to about ordinary high water level, the accu-
mulation of material subsequently takes place at a very slow rate, as the condi-
tions are then unsuitable both for salt marsh and land plants. BusheB, trees
and the higher species of vegetation will not, as a rule, grow on marshes covered
at occasional high tides, even by a few inches of sea-water, although there are
important exceptions.

In British Guiana Spartina grasses and Batis are perhaps the most important
plants on the first zone landward of low-water level. Near low-water mark
black masses of sand are often inhabited by iron-snlphnr bacteria, the black
colour of the sand being due to the reduction of sulphates dissolved in water
contained in ferruginous sand. On muddy foreshores of estuaries and bays, there
are sometimes shallows which contain water even at low tide. In such places
several Bpecies of tall, perennial plants grow in dense masses, and accumulation
on the bottom gradually takes place.

Spartina grasses are the most valuable grasses growing on the foreshore
between high water of ordinary neap and spring tides. In sheltered bays and
estuaries these grasses are very effective, in causing the reclamation of tidal
muddy foreshores. Altogether there are about 1 8 known species* of Spartina,
mostly natives of America. With a few exceptions they grow on Salt mashes
and muddy foreshores which are covered by spring tides. In places these
grasses rapidly overrun large areas, hundreds or even thousands of acres
of foreshore ; their extensive roots fix the shore material and prevent it
from being washed away. The mass of leaves to some extent breaks

*With reference to species of Spirtiim grass referred to, it may be noted that the
Department of Agriculture carried out trials on the foreshore some years ago with S. Town-
wrtihi, a species winch hits proved of enormous value as a foreshore colonist on the coasts of
England, France and Holland, and which was recommended for trial in other parts of the
world. i Though it grew well in the Colony when established, it was however unable to com-
pete with the indigenous speciess S. bratiliemU, which completely smothered it when the two
came into contact. References to the two trials may be found in the Govt. Botanist's report
for the years 1931*83 inclusive, and a summary of trials with these two apecies, made here and
w other mpat countries, was published in the Kev Bulletin of Mite. Information, 1936, p, ‘21,

AORIOT&TTTBAL JOTJEKAL OF BRITISH OSTIA**,

[IM*

the force of the waves, slows down the current, and causes accumulation
of material on the shore which is thus gradually raised. The decay of the
leaves and roots forms a humus, and therefore, while the shore level is
being slowly raised, a soil is being formed which, when the level is raised high
enough, will be eminently suitable for the other kinds of plants. Numerous
shell-fish and animals dwell among the grasses, and their remains help to raise
the shore level.

In Dr. Stapf’s opinion Rice Grass mainly spreads by seed. The grains fall
with the spikelets, which float, and are transported by the tides and currents to
neighbouring shores, where they germinate. He suggests that the seeds may
possibly lie in the water over the winter and germinate in the following spring.
The seedlings soon grow into tufts, with plenty of stolens radiating in all
directions, and anchor themselves to the shore by long thread-like roots which
descend vertically. There is no difficulty in transplanting Spartinas.

Most grasses and plants which grow in salt water die as soon as the accumu-
lation has been raised to high-water level ; an occasional covering of salt water
being necessary for their existence. Tidal forest trees, however, in sheltered
places grow and accumulate detritus from below low- water to above high-water
mark, thus completing the reclamation of the foreshore and sea- bed without
artificial aid.

On sheltered parts of the sea-coast and in estuaries and lagoons, in or near
the Tropics, certain species of trees are \ery effective in causing accumulation
from below low-tide to about high-tide level. Unlike most vegetation, the tidal
forest trees will in sheltered places grow in moderately deep water.

The tidal trees which fringe the coast line on sheltered shores in bays and
estuaries form a dark-green dense belt of low trees, which, in addition to causing
the reclamation of tidal foreshores, also tend to protect the coast from slight
erosion. The trees raise the surface of the sea-bed and foreshore in much the
same way as the lesser forms of vegetable life that is, by slowing down the
currents and causing the deposit of sand and mud which is carried in suspension
in the water. The roots of the trees also accumulate a lot of material which
moves along the bottom by the action of currents and waves. The decay of the
large number of marine animals which dwell among the foliage and leaves con-
tributes debris to the rising surface level, and rich black soil is thus formed,
which between the tide limits is evil -smelling and abounds with bacteria. Several
species of Crustacea burrow in the subsoil, bury dead leaves, and play a similar
part to that of earthworms on land.

Warming, in his work on the Ecology of Plants, states that tweniy^six
species of plants grow in tidal forests. Tidal forests arc often called “ man-
grove marshes ” as the mangiwe trees (species of Rhizophora) are the most
important trees inhabiting tidal waters in the Tropics (Fig. 4). The trees arrange
themselves zonally to a certain extent, the species of Rhizophora being generally
found iu the deepest water. The 44 air-roots ” or 44 prop-roots ” are an interesting

Plate v,

Fig. <♦. Sand spit formed at Golden Fleece, Kssequibo, in January. Fd.io. Vegetation
just starting to establish itself.

Fig. 10. — Landward \ iew from Golden Fleece groyne. Kssequibo, in January. 11)35.

Plate VI.

| i^r n — Luuiw ii<1 M(\\ fiom (»oldm I hue h noMu I nsmjuiIh) m Si ptembti lbt,> r l lie
tisunui tuid dim 1^ pi ntn ilh hidden

I 12 — \itui d Mild d id shell i mbmkment it Woollmds lust Coist Dtmtriri

wti vm of vmv ution for coast protection.

feature of many of the tidal trees. There are either erect or kneed branches of
the roots which project above the shore surface. They are provided with
minute openings (stomata or lenticles) which allow air to pass in and be carried
by means of passages in the soft spongy tissue to the roots embedded under the
shore. The “ prop-roots ” also serve as supports to the trees and securely fix
them to the sea-bed. The power of resisting bending caused by wind or sea is
much greater in the case ot trees having aerial roots than those having a
main stem only.

The tidal forests multiply by seeding and also by means of runners. In
several species of Rhizophora the embryo plant grows into a more or less
developed plant while still attached to the parent tree. Long radicles emerge
from the seed and descend rapidly towards the shore surface where the latter
may establish itself before falling off the parent tree. If the seedlings break
loose and fall into the water or mud, their club-shaped pointed roots enable
them to fix themselves into the mud ; or if the water is too deep, the seedlings
are transplanted by the current, and may strike root on another part of the
coast. Some of the seeds of the tidal forest trees are provided with devices
which enable them to float.

On the E ist Coast, Demerara, courida trees grow freely above mean sea level
and in the estuaries of the large rivers mangrove is usually very plentiful.

C nirida is useful in building up and consolidating a muldy shore subject
only to overflow at high spring tides, but, on the other hand, it is useless to
prevent violent erosion by wave action. If severe erosion starts the courida
stumps are very harmful, and increase the rate oi erosion. In the past it has
been necessary to spend large sums of money in removing courida stumps from
the East Coast foreshore (Figs. 5 and (»).

From a health point of view the coast-line of a belt of courida is, in
populated areas, very objectionable. When an exposed foreshore, subject to
wave action, has built up to about high tide level, the courida has practically
completed its work in causing accretion and there is no objection to its removal
provide l all the stumps are taken away ami the foreshore planted with spartina
or other suitable grasses which will cover it. In estuaries, where the shore is
sheltered from violent wave action, inmgrose trees are a \ery effective protec-
tion against erosion aud should not be cut down.

On parts of tho Islands of Wakenaam and Leguan the mass of mangrove
roots effectively protects the coast from erosion by current action. In many
cases erosion has been started by cutting down the mangrove at the koker
outlets to provide a landing place for boats. Efforts are now being made to
re-establish the growth of mangrove in abandoned boat landing places by form-
ing a pallisade of sticks or bamboo and planting young mangrove trees behind.
The pallisade is at first necessary to protect the young plants (Figs. 7 and 8).

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[IX, 1.

In connection with this matter it is important to differentiate between the
effect of a mass of tree stumps or roots on a shore subject mainly to current
and a shore subject to heavy wave action. On the protected shore subject
chiefly to current action tree stumps and roots are effective in slowing down
the current and preventing erosion. On shores which suddenls y become subject
to violent wave action the tree stumps and roots cause erosion and aid the
destructive forces o£ the waves. Holes are formed round each root stump
lowering the foreshore and causing the uneven surface to be more easily
attacked by waves.

Sand embankments and sand spits enclosing bays are sometimes formed where
there is a predominant littoral drift in one direction. When the sand bar has
been raised to mean tide level vegetation actively assists in raising the shore
level landward of the spit or embankment. Figs. 9, 10 and 11 illustrate a sand
spit formed at Golden Fleece, Essequibo Coast, in 1935 and the action of vegeta-
tion in building up the shore.

Sand and Shell embankments.

In the actual formation of sand embankments abpve high water level
vegetation plays a very important part. On foreshores where there is sand it
is dried by wind an*l sun at low tide, and as soon as it becomes dry the wind
is able to transport it inland. As a general rule, the prevalent winds are onshore,
and such winds are more effective in moving sand inland than the loss frequent
seaward winds in moving sand back again.

Sand embankments on the coast-line above high water level are generally
formed by the accumulation of sand against some obstruction. Trees, shrubs,
grasses, fences &c., may occasion the lodgement of sand in considerable quantities.

On the seacoast, the formation of embankments is chiefly due to vegetable
life. The various kinds of grasses which grow in sand just landward of high
water are very effective sand collectors. Each plant or group of plants forms
in effect an openwork fence and collects sand in the manner previously
described. Many of the various grasses which thrive on sandy coasts grow
upward as the sand accumulates ; thus in time dunes of considerable size are
formed.

Where there is insufficient vegetation to fix sand embankments properly
as they are brought into existence on the coast margin, they are rapidly moved
inland. InEurope large areas of fertile land and even villages have been
completelJjjBhgwhelmed bv the advancing sand; and sand deserts as a con-
sequence iOT^Pd. The inland movement of unfixed sand embankments has
often resulted in the inland movement of high-water line, thus causing serious
erosion of the coast as well as the devastation of the land. In places where the
sand blown inland from the foreshore not replaced by sand brought in by sea
action or littoral drift, the erosion of foreshore naturally takes place,

1) XiUmlsiml tinWinkineni »t EsMqmbo, o\eu»io\\n with Ipomwa h/loba

Tint USE OF VEGETATION FOR COAST PBOTlOTIOir.

The velocity of the inland travel of a sand embankment is the rate of
advance of the crest, which takes {dace by the accumulation of sand on the
steep lee slope. The supply is brought in two ways : firstly, by the rolling of
coarse sand grains over the crest ; and secondly, by the deposit of part of the
the vegetation flying sand caught by the eddy and not tossed away again.

If covered with vegetation sand dunes form a consolidated barrier against
the encroachment of the sea. The roots of the various grasses and plants bind
the surface, and the foliage catches and retains sand abstracted from the fore-
shore by wind action (Figs. 12 and 13). The dune thus grows in height and width,
the vegetation in many cases accommodating itself to a rising surface level.

On the Gascony coast of France, coast sand dunes were formerly moved
inland by wind action, causing erosion of the coast and devastation of the land
by the formation of a miniature Sahara. All this, however, hffg been changed
by the work undertaken by the French Government, and insteg# Af vast areas
of bare desolate sand, there are now productive pine forests. The success of
this work was largely duo to the initiative of a French engineer, M Bremontier,
who, over a hundred years ago, devised a system for fixing and reclaiming the
Gascony sand dunes.

Documentary evidence shews that at the time of the first Roman reclama-
tion of Holland the sand embankments were clothed with trees on their land-
ward slopes and in places even partially down the seaward slope. Old
geographers describe forests on the dunes extending to very near the sea. There
is little doubt that not realising the value of the trees for fixing the dunes and
preventing their inland movement, the trees were cut down with the result
that in the Middle Ages chroniclers refer to the drifting sand embankments.

The growth of grasses and small shrubs on the sea face of the dunes down
to high water level of spring tides, is essential to bind the sand and collect fresh
inblown sand.

In the past the vegetation wa9 often damaged by pedestrians and cattle.
Now very stringent laws are enforced in Holland to ensure the careful preserva-
tion of vegetation and the coast is constantly patrolled.

The efficiency of vegetation in consolidating sand dunes and preventing
coast erosion has for many years boen widely recognised, and numerous lawg have
been passed to prevent its destruction.

In the reign of Queen Elizabeth an Act was passed to prohibit the des-
truction and to encourage the cultivation of vegetation on sand embankments.

In early times there were laws in force in numerous manors in England to
prevent injury to coast sand embankments. The Records of the Manor of
Ingoldmells in the County of Lincoln, shew that in the reign of Edward II, five
Orders of Attachment were made against various persons for “ doing damage in
pasturing on the sea banks, for mowing the dunes and herbage outside the
bank of the sea, against the defence of the sea for the salvation* of the
country, at the Manor Ingoldmells ”

STATUS OF THE AMAZON FLY IN BRITISH GUIANA, 1937.

L. D. CLEARE, F.R. ENT. B.,

Entomologist,

Vrjiartmcnt of Agriculture, British Guiana.

Introduction.

It ia necesaary to follow for a number of year8 the 8tatua of an introduced
parasite in its new environment before an opinion can be formed as to the role
the insect is playing in combating the pest for which it was secured.

Examinations made on sugar estates at different times after the introduction

of the Amazon Fly into this country showed long since that the insect had

established itself not only in sugar-cane but also in rice, and as regards the

former crop at least was parasitizing a fair proportion 'of the Diatrara

sacchuraUs in that host plant.

A survey carried out about the middle of 1935 by Mr. F. A. Squire, while
engaged as Supernumerary Entomologist in this Department, showed further
that some two years after the introduction of the parasite and the colonization
of the sugar estates the insect was still doing good work. The results of this
survey were not published.

About a year ago it was considered desirable to undertake another survey,
and in January 1937, the work was commenced, continuing, as opportunity
allowed, to January 1938. In the present survey it was not possible
to carry out examinations of all + be sugar estates in the Colony owing to the
pressure of other work and the limited staff of assistants, but a total of fifteen
sugar estates was examined during the survey extending from Pin. Skeldon
on the extreme east of the Colony to Pins. Versailles and Schoon Ord on the
West Bank of the Demerara River. It is believed, however, that both the
number of estates examined as well as the area o\er which they are extended
are sufficient to allow the results to be considered as being representative of the
general conditions over the sugar-growing area.

As regards Pin. Albion, llerbice, the survey of that estate was carried out
in conjunction with Mr. H. W. B. Moore, Entomologist of the estate, who
undertook the field collections of material.

Colonization of the Sugar Estates, 1933-35.

Before dealing with the present position of the fly, some information As
to the introduction of the insect and the subsequent colonization of the estates
will be given. ,

Status Of tab amajson ?ly in British Guiana, 1937.

The first consignment of the Amazon Fly arrived in British Guiana from
Brazil on 30th August, 1933, and between that date and 31st October, 1933, a
total of six consignments was received totalling 3,000 puparia, and from these
1,409 flies were secured. From these initial stocks some liberations were
made directly into the sugar-cane fields, as well as material obtained to start
extensive rearing operations.

Rearing of the fly was commenced at Headquarters Laboratory on the
Sugar Experiment Station as early as 21st September, 1933. Later as the work
progressed laboratory assistants were trained in the technique of rearing the
insect and field laboratories sot up in conjunction with the different estate
authorities on ten sugar estates scattered over the sugar area of the coastlands.

These estate laboratories served to stock the plantations on which they were
situated, and which in most instances were at too far distances from Head-
quarters to be stocked from there. Such estate laboratories were situated in
the county of Berbice and on the East Bank, West Bank and West Coast,
Deinerara. All the estates on the East Coast, Demerara, besides a few on the
East and West Bank Demerara and in Berbice, were colonized solely with flies
reared at the Headquarters Laboratory.

During the period these laboratories were in operation a total of over
379,000 flies was reared in all laboratories, of which over 18,000 were produced
at Headquarters Laboratory. As regards Headquarters Laboratory, work ceased
in April 1935, and no flic3 were supplied to the estates which were colonized
from this laboratory after that date. Many of the estate laboratories continued
rearing for a few months longer, however, but by September or October 1935
practically all had ceased work in this direction. There were a few exceptions
to this where the rearing of flies continued for some time longer, namely, Pins.
Port Mourant and Leonora to November 1935, Pin. Albion to December 1935
and Pin. Blairmont to June 1936.

Table I gives the number of flies distributed to the estates from Head-
quarters Laboratory, between September 1933 and April* 1935, and Table II
shows the number of flies reared in all laboratories, between September
1933 and November 1935.

For about three years, therefore, as far as the East Coast Demerara estates
are concerned, and from about the end of 1935 in most other instances, the fly
has been continuing on its own, under conditions that it must meet and survive
if it is to exert any control on Diatraea m the Colony. Just how well it has
accomplished this the present survey will show, in part at least.

Method of Survey.

In explaining the method used in obtaining data in the present survey
some acconnc of the habits of the moth-borer and of the fly will help. In the
early stages of the attacks of moth-borer on sugar-cane the larv® bore into the

Tables I. — Amazor Flies distributed from Headquarters Laboratory to Sugar Estates for Colonisation

or as Breeding Stock, 1933-35.

Principally Breeding Stock.

NO. OF FLIE»n

&¥ATU 8 OP THE AMAZON tit lit BRITISH GUIANA, 1931 15

TOTALS

COC »H

“’SSS

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105,075

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SSSSSS 1 ''*'*

271,238

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Wales

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1,445 :
| 2.357

! 2,295

2.260
2,521
1,421
1,796
696
803

l 810

| 639

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1933

October
November ,
December

+»

1934

Janaary

February

March

April

May

June

July

August

September

October

November

December

5 III

O' §

H-

April

May

June

July

August
September
October *

No\ ember
December

16 , AGRICULTURAL JOURNAL OF BRITISH GUIANA. £ IX, 1.

young stalks and destroy the central leaf, producing what is generally termed a
“deadheart.” When the stalk has reaohed the stage of jointing, however, it is
not normally killed, the moth-borer larva: boring into such stalks and tunnelling
them to a greater or less extent.

The Amazon Fly in attacking the moth-borer larva: deposits eggs or larva:
at the entrance of the moth-borer tunnels or in their vicinity. The larva: so
deposited, directed either by smell or reacting to some other stimulus, enter the
borer tunnels and eventually lind their way to the Dial rani larvae. Having
entered the Dial rant larva: the parasites continue to develop, and by the time
they are ready to pupate the host larva has succumbed so that the parasite is
able to leave the then mere remains of the moth-borer larva. The parasite then
pupates, either about the entrance of the moth-borer tunnel, or sometimes out-
side behind a leafshoaf, or even, occasionally, at the base of the plant on the
ground.

To obtain an estimate of the work of the parasite in the field it is necessary
to ascertain the number of the host parasitized, including such of tho parasites
as are found in the pupal stage at the time of the examination.

For this purpose field examinations were made, and data compiled there-
from. In these examinations fields of between six weeks and two months old
were used, as it was considered that this would be representative of fields which
would be normally worked were “ borer gangs ” being employed in hand
collecting, and would contain a fairly representative Diatuini population
in their young stages.

In each such field the collection of Diatram was undertaken on a fixed
method, which consisted of making collections in the field at 10 places spaced
about equally across the field diagonally. At each of these places the “ dead-
hearts ” in two rows were cut and examined. In each field it was the en-
deavour to obtain at least 100 Dialrara larva 1 in the collection, but if the
Diatraea population was low (as often occurred) this was not always possible
and under such circumstances the examination of the field continued,
cutting “ deadhearte ” from rows in the same areas, for z period of 3 boy-hours.

The Diat ram larvae were collected from these “deadhearts”— both D. soc-
charalis and D. canHla were secured, as were also the living Diatraea pupae and
Amazon Fly puparia ; the result wa3 noted on a form, and the material brought
back to the labatory for examination.

Diatraea larva: obtained in the field examinations were subsequently dis*
sected in the laboratory and the actual parasitism noted, while the Amazon Fly
puparia collected were kept for emergence of flies and hyperparasites.

On each estate at least twelve fields were examined (Pin. Farm excepted
where only seven fields were examined) for preference on consecutive days, but
in two instances suoh examinations comprised a larger number of fields and/or

STATUS OP THE AMAZON PLY IN BRITISH GUIANA, 1037.

were taken at two different periods. There was no selection of fields beyond the
limitation of age, which has already been mentioned, and an attempt to have the
number of fields examined distributed as nearly as possible equally among the
stands, namely, plants, first, second and third ratoons. Usually the fields on the
estates which complied with the conditions as regards age were listed by the estate
authorities at the beginning of the examination of each estate, and from such lists
twelve were selected at random so as to be distributed over the cultivation.

Results of the Survey.

Fifteen estates in all were taken in the survey and on these a total of 212
fields were examined, comprising 88 plant fields, 54 first ratoons, 56 second
ratoons and 14 third ratoons. Of the total of 212 fields, in 155 fields (73.1 per
cent.) the Amazon Fly was found parasitizing either 1). saccharalis or D. canella
or both, 144 fields showing a parasitism of 1). saccharalis only, but no field was
found in which only I). canella was parasitized.

In these fields a total of 37,332 “ deadhearts ” were cut out, of which 20,998
or 56,3 per cent, were empty. Of the remainder, 14,274 (37.9 per cent, of the
total) contained living Diutraea, in the proportion of 6,271 or 43.9 percent,
D. saccharalis (the black-headed borer) and <8,003 or 56.1 per cent. 1). canella
(the yellow-headed borer), 2,060 or 5.5 per cent, of the “ deadhearts ” were the
result of “ Other Causes ” including white grubs (hard back beetles) and rats.

Table III gives the details of these figures as regards each estate.

In 5,371 D. saccharalis found in Positive Fields, 863 or 16,0 per cent, were
found to be parasitized by the Amazon Fly at the time of examinations of the
fields (“ Current Parasitism of Positive Fields ”) the parasitism ranging from
'3.4 per cent, to 36,2 per cent. While of the total of 212 fields, 39 or 18.4 per
cent, showed parasitisms of 1), saccharalis of 30 per cent, and over. If, however,
all the fields examined are included, both positive and negative 0* Current
Parasitism in All Fields ”) the parasitism works out at 13,cper cent. L>. saccharalis.
see Table III.

The parasitism for D , canella , as expected, was low, 0.32 per cent, for
“ Positive Fields” and 0.23 per cent, for “ All Fields.”

As regards the individual estates little need be said. It will be seen that the
results of the Burveys of Pin. Port Mourant and Pin. Blairmont have been given
in two sections'each, and some explanation in this respect may be of value.

On the occasion of the first survey at Pin. Port Mourant the parasitism was
particularly low, and much lower than examinations on previous occasions had
revealed. As that examination was made during a dry period it was
thought that the low parasitism might be attributed to weather conditions.

Tabu III.— AMAZON FLY SURVEY, 1937-38— RESULTS OF EXAMINATIONS OF SUGAR ESTATES.

20 , AGRICULTURAL JOURNAL Of BRITISH GUIANA. [IX, 1.

Accordingly it was arranged that at a later date when wetter conditions
occurred, another examination of the estate would be undertaken. The
second examination, made under similar conditions in all respects except
as regards weather conditions, gave a much higher parasitism, and it is believed
that this higher figure was due primarily to this cause.

The position at Fin. Blairmont was somewhat different. On that estate the
first examination, which was made under wet conditions, showed a high parasi-
tism, but owing to the pressure of other work, had to be discontinued after only
four fields were examined. In January 1938, Mr. G.M. Eccles, Manager of Blair-
mont Estate, reported a severeiattack of Diatraea in certain fields and opportunity
was taken to examine these fields to ascertain the position with regard to the
parasite, and at the same time other fields on the estate were examined to complete
total of twelve fields and the survey of the estate.

As to the conditions connected with this outbreak, it would appear that to
some extent at least the attack was associated with a heavy growth of the grass
Echinochloa crusgalh cruspavoris (HBK) Hitch. v.hieh occurred after the fields
were taken in from water-fallow and in which Diatraea mccharalis was present.
In addition, the four fields attacked are situated at the moBt distant part of the
estate, and unlike other fields, have no immediately adjacent fields ; there would
be little possiblity, therefore, of flies spreading into these fields from outside, and
the population introduced in the normal way with the tops may not have been
sufficient to deal with the position, or found conditions unfavourable.

Number of Parasites Per Host.

Records were kept during the survey as to the number of parasites per host.
Of a total of 803 Diatraea saccharalt * records, it was found that 313 or 39.1 per
cent, contained only a single parasite, 203 (30.3 per cent.) contained two
parasites, 06 (7,0 percent-) contained three parasites, 17 (1.9 percent.) four
parasites and onlj 4. (0.3 per cent.) contained five parasites per host.

The pnparia of the fly found in the field agreed very closely with these
figures and were in the proportions of 59.4, 31.4, 7.5, 1.4 and 0.3 per cent, for
one, two, three, four, and five parasites per host respectively.

Hypbrparabitism.

In January 1937, Mr. H. W. B. Moore recorded a hyperparasite of the
Amazon Fly from Pin. Albion, Berbice.

This appearance of a hyperparasite was not unexpected for it had long been
known that the native fly parasite of Diatraea , Leskwpaipus (Slomatodexia)
diadema Wied. was attacked by the hyperparasite Signiphora diplerophaga Girault,

STATUS OF THE AMAZON FLY IN BRITISH GUIANA, 1937.

and the possibility of this insect attacking Metagoniatylnm was well
recognised at the time of the introduction of the Amazon Fly. ThiB was con-
firmed when a determination of the insect was made by Dr. C, Ferricre of the
Imperial Institute of Entomology.

In addition. Squire, in his report of 1935, had mentioned the finding of a
puparium of Metagon i sty turn which apparently had been attacked by a hyper-
parasite although he did not obtain any specimens of the insect.

Accordingly during the survey precautions were taken to secure hyperpara-
sites in order to obtain data as to the prevalence of the insect.

On four estates of the fifteen the hyperparasite was obtained, namely. Pins.
Port Monrant, Albion, Diamond and Farm. This would indicate that the hyper-
parasite is well distributed over the sugar area.

Of the 45 fields examined on these estates in 13, or 29 per cent., hyperparasites
were found, while of 1 78 puparia collected, 17, or 9.0 per cent, produced hyperpar-
asites. If, however, the whole Amazon Fly population of these fields is consider-
ed, namely 51 0 larvro and puparia, the percentage destroyed by hyperparasites
would only be 3.3 per cent.

Table IV gives the details as regards examinations of the ostates in relation
to the hyperparasitism.

Table IV.— Amazon Fly Survey, 1937-38. Hyperparasitism of Amazon Fly
Puparia by Siguiphora dipterophaga.

| No. of Fields.

Estate.

Examined JlXT

Port

Mourant

Albion

Diamond

Farm

Totals

Puparia.

Amazon Fly

Population
Lame and

Total.

With

Hypers.

Pupte.

1C>3

148

115

1 78

510 1

Hyperparasitism
Per cent.

Amazon

Fields.

Puparia.

Popula-

tion.

•*

250

8.4

20.0

7.9

333

13 5

5.6

43.0

3,5

27.1

1 9.G

3,3

Other Parasites.

Other larval parasites, Bmconids, were met with during the survey and note
was taken of these also. In the saccharalis population in all fields numbering,
as we have seen, 0,271, Bruconid parasites to a total of 59 or 0.94 per cent.^ were
obtained, while for a cnnella population of 8,003, 24 Braconid parasites or 0.3

per cent, were present.

28 AammmM JomxiAi of samss wiawa [IX t*

With regard to the native fly parasite Lesktopalpus, unfortunately ho dell
available. While it is definitely known from observations and examinations
undertaken daring the period covered by the survey that Leskiopalpus dots
occur in both the East Coast and East Bank districts, none of the insects was
obtained in the examinations which actually constituted the snrvey. Accordingly
no figures are given for the present prevalence of the insect.

Conclusions.

From the results given above we may draw some conclusions as to the
present status of the Amazon Fly in the Colony.

As the result of this survey it has been found that not only is the
Amazon Fly present in the fields bnt that it occurred in 73 per cent, of the fields
examined. That in such fi elds the fly was parasitizing an average of 16.0 per cent,
of the D. well iralis population and 0.32 per cent, of the D. canella population, and
taken over all fields these figures were 13.7 per cent, and 0.23 per cent, respective-
lv. The parasitism ranged from 3 4- per cent, to 36.2 per cent, for Positive
Fields” and 2 0 per cent, to 33.6 per cent, in “ All Fields.” In 18.4 per cent,
of “ Positive Fields ” the parasitism of D. sarrharalis was 30 per cent, and over.

Commenting on the larval parasitism, Myers (1 ) in his very thorough review
of the Diatrata' situation in 1031, stated that the combined parasitism of the
eight important parasites was 6 9 per cent, of the borers in cane. The larval
parasitism by the Amazon Fly of 16.0 per cent. D. saccharalts in the present
survey must, therefore, be considered as very satisfactory.

As regards the other larval parasites, the Bracomds were present only to the
extent of 0.9 per cent, in D. sac char al is and 0 3 per cent, in D. canella.

Unfortunately no data are available for the native fly parasite Lesktopalpus
in connection with the present survey. It muBt be made clear that the fact that
no parasitism by this insect was obtained in the survey samples does not indicate
the disappearance of this insect. On the contrary, during the period covered by
the survey, as stated previously, the fly was observed in the field, but its absence
in the survey samples does indicate its comparative scarcity at the time.

That the prevalence of this insect is affected by weather conditions there
can be little doubt, bnt it shonld be pointed oat in addition that the only
authoritative statement we have on its prevalence is that of Myers (1) that, “The
Paratheresia and Stomatodcxia are together responsible for a mortality of 3.2 per
cent, borers in cane, but they apparently do not extend activities to the small
grasses.”

It has been stated that Lesktopalpus {Stomatodexia) does not occur in Berbioe,
The fly is no doubt of rare occurrence there but the writer reared this insect from
Dmtraea at Pin. Blairmont, Berbice, in February 1922, and since then tbs
insect has been on other occasions taken in the same locality. From localities
east of the Berbice river there appears to be no records of its oocnrrenee.

OTAttJl 0f TOT AXAZOH FLY IS BRITISH (JUT AHA, 1937.

On font of the fifteen estates examined hyperparasites were found.
Sypirpemitism of Amazon Fly pttparia occurred in 27.1 per cent, of the fields
op tbs estates on which it was found ; and 9.6 per cent, of the poparia were
attacked.

In this connection it should be pointed out that the hyperparasitism, occur-
ring as it does to puparia, takes plaoe after the parasite has done its work and killed
the host larva. The destruction of the host population to the extent of 16.0 per
oent. (in this snrvey) has already taken plaoe. Farther, if the hyperpar&sitism is
calculated on the whole Amazon Fly population it is only 3.3 per cent.

The snrvey has shown also, to some extent at least, that there is a variation
of the prevalence of the fly dne to weather conditions, and so serves to confirm
previous observations of this nature.

There also appears to be a somewhat uneven distribution of the fly on
estates, and occasionally there have been severe attacks of Diatraea in fields.
This is to be expected for some time after the introduction of a new species, and
until it settles down in its new environment. That, since its introduction, there
have been so few ontbreaks of Diatraea speaks well for the fly. The fact
should not be lost sight of that the large majority of the sugar estates in the
Colony (there are two or three exceptions) have only on rare occasions employed
a “ borer gang” since the colonization of the estates with the Amazon Fly was
completed in 193. r >.

Thompson (3) tells ns that even when conditions are relatively favourable to
the parasite the course of events may not always present a very satisfactory
appearance and says :

“Perhaps the most important point to remember in this connection is
“ that daring the period which follows the introduction and establishment
“of a species, and the time when it has reached the highest population which
“it can attain in the area, there is an intermediate period dnring which
“ the species increases slowly but steadily in numbers, but during which
“ this increase may be masked by local irregularities of various kipfls, so
“ that in one locality the parasite may appear for a certain length of time to
“ increase with extreme rapidity, while in another it exerts absolutely no
“ effect, after whioh it may disappear from the first locality and become
“abundant in the second.”

In the survey as undertaken it must be borne in mind that the data obtained
represent conditions as found at a particular time and stage in the growth of the crop.
It is, therefore, not to be considered as neoessarily the best that the inseot is capa-
ble of performing or even the best that it is doing at the present time. In-Act the
contrary Is the case for we have found fields in the present survey in which as high
as 80 per gent, of the Diatraea saaharalis population has been parasitized, while

24 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 1.

18,4 per cent, of the positive fields showed parasitism of 30 per cent, and over,
and even the canella parasitism is often higher than has been found in
the examinations now reported upon. Had the examinations been made at a
later stage in the growth of the crop there is more than a probability that the
parasitism by the Amazon Fly would have been considerably higher. For that
reason alone it would seem desirable to undertake at a later date more detailed
examinations of a few estates extending over the whole period of the growth of
the crop.

That the Amazon Fly is doing good work in the sugar area the figures given
now leave no room for doubt. There can likewise be no doubt as to the value
of the introduction, nor that the cost of the undertaking haB been amply repaid.

Beyond this we should not go at present, remembering Thompson’s advice
that “ The entomologist should be as much on his guard against premature
reports of success as against premature complaints of failure.” It is still too early
to draw conclusions or make statements as to the future work and destiny of
the parasite, and mere guesses, pious opinions, or statements based on scanty
data, are of no value. i

References.

(1) MYERS, J. G. (1931). A Preliminary Report on an Investigation into the

Biological Control of West Indian Insect Pests. E.M.B. 42.
H.M. Stationery Office, Lbndon, July 1931.

(2) Squire, F. A. (191>). Colonial Development Fund, Progress Report on the

Present Status of the Amazon Fly in British Guiana.
(Unpublished Report).

(.1) THOMPSON, W. R. (19.10). The Biological Control of Insect and Plant Pests.

E.M B. 29. H.M. Stationery Office, London, June 1930.

PLANT LEGISLATION IN BRITISH GUIANA AND
THE CARIBBEAN COLONIES.

L. D. CLEARE, F.R. Ktrr.g.

Entomologist , Department of Agriculture, British Quiana,

Within recent years, as the resalt of research in entomology and plant
pathology, there has come aboat a better understanding of the pests and
diseases affecting plants and the manner in which they are spread. With the
acquisition of this knowledge there has followed the development of measures
for their control and prevention, and to-day there are few countries in the
world where efforts are not made to combat such pests and diseases of plants
as occur within their borders and to prevent the introduction of others from
outside.

In order to do this effectively, it has been found necessary to enact legisla*
tion, and plant protection legislation is now almost universal. In the
British Empire alone such legislation is extensive, and it will be seen from
the summary which follows that ev»n in the comparatively small area which
is dealt with here it is not inconsiderable.

The countries of tropical America, including British Guiana and the
British Colonies of the Caribbean, have had their full share of devastating pests
and diseases in the past. It is not surprising, therefore, that these countries have
enacted legislation, the aim of which is to prevent the introduction of pests
and diseases from areas outside their borders and to control them where they
occur within.

In the summary given here, an effort has been made to bring together in
a concise form the existing legislation as it affects this Colony. For convenience,
the information has been grouped into two parts, namely : (1) that existing in
British Guiana both as regards internal matters as well as import and export
prohibitions and (2) that referring to the British Colonies in the Caribbean.

With this summary it should be possible for individuals concerned either
with the import or the export of plants and plant products, including fruit and
vegetables, to ascertain easily what restrictions are in force with respect to
any particular, or to all, products in the area. It should be borne in mind,
however, that while the summary is complete at the present time, alterations
and additions are made from time to time, so that in future it will be necessary
always to obtain information as to any amendments which may have taken
place sincf the compilation of the present summary.

aobhhtwwui. mqsval m vsamm Rtnm
BRITISH GUIANA,

i*m 3U

SUMMARY OF LEGISLATION AFFECTING AGRICULTURAL

INDUSTRIES.

1. PLANT QUARANTINE.

I. External — Import Prohibitions.

A. PROHIBITED ARTICLES, INCLUDING PLANTS, SOIL AND
PACKAGES AND ARTICLES CONNECTED THEREWITH.

Articles prohibited.

Country of origin.

Reasons for
prohibition.

Index of
Legislation.

Sugar canes and any plants or
parts thereof

Ail countnes

Prevention of in*
troduction o f
disease

Order-in-Counci l
under Ordinance
No. 37 of 1936

Plants of grasses of any kind

»»

Earth or soil or any thing
packed therewith

Pimento and Bay tree
( Pimenta acris )

J amaica

Rust disease

Notioe in Official
Gazette dated
December 3, 1936

Citrus material (including
fruit)

United States o f
America

Citrus canker (Php-
(omontiH citri )

Order-i n-C o u n c i 1
under Ordinance
No. 37 of 1935

Fruit (except plantains, nuts
and dried, canned, can-
died and other preserved
fruits)

Vegetables (except onions.
Irish potatoes and canned
or preserved vegetables)

All countries except
British Isles,
Canada and the
British West
Indies not in-
cluding Bermu-
da and the
Bahamas

Moditerianean
Fruit Fly ( Cera -
tith capital a )

Order-i n-C o u n c i 1
under Section 28
of Customs
Ordinance Cap.
33 dated May
19, 1930, as
amended by
0 rder-i n-Counct 1
dated Aug. 20,
1934

Raw coffee

All countries on
the continent of
South America

Coffee berry-borer
(StephaHoderes
nampei Ferr.)

Regulations made
under Ordinance
No. 37 of 1935

*U4* tmisbims nr sxnm wiaita ahd tbs Caribbean oolojjibs. 27

B. PROHIBITED ARTICLES, EXCEPT UNDER LICENCE.

Article* prohibited.

Country of origin*

Seasons for
prohibition.

Index of
Legislation.

Sugar canes and any plants
or parts thereof (import-
ed by ti»e Director of
Agriculture for scientific
purposes)

All countries

Prevention of in-
troduction o f
disease

Order-in-Council
under Ordinance
No. 37 of 11135

Banana and plantain suckers

»»

Haw Coffee

ill countries other
than South
America

Coffee berry-borer
(Stephanoderes
hampei Ferr.)

Order-in-Counci 1
under Ordinance
No. 37 of 1936

Bees and Beekeepers’ stock

All countries

Prevention of in-
troduction o f
disease

Regulations made
under Ordinance
No. 38 of 1935

C. PERMITTED ARTICLES, PROVIDED THESE HAVE PASSED
INSPECTION BY THE AGRICULTURAL DEPARTMENT.

Articles permitted.

Country of origin.

Index of Legislation.

Garden seeds

All countries

Ordor-in- Council under Ordi-
nance No. 37 of 1935

Plants, seeds, cuttings, bulbs
or other plant parts in-
tended for propagation

28 ‘ * AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 1.

II. Internal— Control of Disease and Tests Within the Colony.

Diseases and Pests.

Locality.

Index of Legislation.

Bnmoli ft Bophorae L. Generally

(Coconut Caterpillar)

Mamsmius pernicionuti Stahel. North West District
Witchbroom Disease of
(Cacao).

Notice in the Official Gaictte
under Plant Diseases and
Pests Regulations 19.%
making these notifiable
diseases and pests.

2. MISCELLANEOUS LEGISLATION AFFECTING
AGRICULTURAL INDUSTRIES.

Measure.

Wild Birds Protection
%

Government Lands
Orchids and Haiari

Botanic Gardens
Agricultural Shows, etc.

Object

Close season ; prohibition of
export, killing and sale

Prohibition of export of

Control of

Control of public gardens and
grounds and Government I
Agricultural Stations and j
holding of shows

Index of Legislation.

~ < — •

Cap. 273 as amended b\ Ordi-
nance No. 27 of 1934

Regulation 70 of Croun
Lands Regulations 1919

Government Botanic Gardens
Regulations 1936

Ordinance No. 34 of 1935

PLANT LEGISLATION IN BRITISH GUIANA AND THE CARIBBEAN COLONIES.

PLANTS AND PLANT PRODUCTS, Ac., EXCLUDED FROM

BRITISH GUIANA.

Prohibited Importations

Country of origin.

Sugar canes and any plants or partb
thereof

Plants of grasses of any kind
Earth or soil
Pimento and Kay tree
Citrus material including fruit
Raw Coffee

Banana and Plantain suckers

Plants, bulbs, seeds and other propaga-
ting material

Bees and beekeepers’ stock

Garden seeds

Fruit

All countries

Jamaica
U.S A.

All countries prohibited except under
licence. South America absolutely
prohibited

All countries

All countries except British Isles, Cana-
da and the British West Indies (not
including Bermuda and the
Bahamas)

tqunmui jomsiL <* «“*“* «"“*• [K ' l

PWJW utoisufioN m British guiana and the Caribbean colonies. 31

AGRICULTURAL JOURNAL OF BRITISH GUIANA,

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iGRICtrLTtJfiAL JOURNAL 07 BBltlBH GUIANA

Plant legislation in British guiana and the Caribbean colonies.

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Law of 1910 | Zealand

CARIBBEAN COLONIES.

SUMMARY of LEGISLATION IX FORCE RELATING TO THE IMPORTATION OF PLANTS. — (Con Id).

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[IX, 1.

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PLANT LEGISLATION IN BRITISH GUIANA AND THE CARIBBEAN COLONIES. 37

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SELECTED ARTICLES*

PRESIDENTIAL ADDRESS *

(Fourth International Grassland Congress ) %

PROFESSOR R. G, STAPLEDON.

Greenness is the subject of my address, for grass is greener and more
variedly and more vitally green than anything in the whole wide world, and
green is the vital colour. Young succulent grass is the prince of feeds. Over
an enormous area of the world grass is the foundation of the agricultural
industry, and perhaps almost everywhere it should be the foundation. Research
may well make this possible — yes, possible everywhere.

Grass (and when I say “ grass ” I mean, of course, grass and clover) proper-
ly used ensures soil fertility, grass marries the soil to the animal and the solid
foundation of agriculture is the marriage of animal and soil. That spells humus.
While again grass properly employed counters the devastating influences of
erosion.

I am proud indeed to welcome you here to grassy Wales. Though Wales,
I hasten to add, is not proud of her grasslands. Indeed, for my own part, and
speaking as one who has spent twenty- five years conducting research on grass-
land in Wales, I must admit I find the condition of the grasslands of this
country as a whole, and not only of Wales, deeply humbling. Rut then Great
Britain, you see, and to the untold benefit of some of you here present, has always
liked to finance agriculture anywhere, everywhere, except within her own shores.

*The 4th International Grassland Congress was held in Great Britain last year, and was
attended by representatives from 37 different countries.

Although the majority of the world's great grassland areas«4ie outside the tropics, yet
grassland plays an important part in the agriculture of every country, and at the Congress the
discussions and demonstrations brought out points <?f general application that every cattle
owner* wheresoever he be, can take to heart.

. mos * 1 diking demonstrations shown to those attending ihe conference

included the changes and betterment in pastureland that can be secured by proper rotational
the possibilities of turning to good pasture, by tillage and manurial treatment, land
which had formerly been regarded as waste and almost valueless, and the remarkable improved
strains of common pasture grass that can be obtained by selection and breeding.

Professor Stapled on’s Presidential Address to the Congress deals with some of
the general problems facing the owner of grassland, and indicates how they are being
faced elsewhere. The owner of grassland should look on it as akin to arable land, to bear a
crop of the proper grasses and these alone, to be manured and subject to rotational treatment,
to be properly drained and irrigated and to be suitably fenced. As is pointed out in the
address, a small ares of pastureland carefully tended can be many times more valuable than
a vastly greater area of uncared-for 4 grassland ’ on which cattle run at will.

E. B. M.

AGRICULTURAL JOURNAL OF BRITISH GUIANA*

[IX, 1.

I have travelled more than a little, and I know something of grasslands
in general, but I have not travelled or seen as much as I should have liked, and
I can express no well-informed opinions on many types of the world’s
grasslands.

I have, however, come to this opinion, and I believe it to be just, nay more,
fundamental, that the only rational approach to the problems of grassland (the
practical problems and the research problems), is the wide regional approach.

The first necessity is to classify our grasslands, and to understand their
interrelations, and then to work and to plan on the basis of clearly defined
regions — natural regions. The proper use of grass and of grassland is a matter
of systems of farming, and therefore of facilities. It is a matter essentially of
the right implements, the right fertilisers, and pre-eminently of the right seeds.
More than this, it is a matter ol usage and custom ; systems of land
tenure ; methods of marketing and a hundred other things, all of which
can only be appreciated properly and tackled successfully on a regional basis.
What is generally essential is to discredit old fashions and to introduce new
fashions. In this country all manner of old-fashioned clauses in leases are, for
example, a great handicap to the introduction of new and long overdue methods.
In the matter of seeds, the essential thing is to use the* right strain of the
comparatively few species that really suit the needs of any well-defined natural
region. To organise; this is by no means an affair only of plant breeding. The
plant breeding to be of maximum benefit should, however, he conducted in the
region it is proposed to serve. It is only by chance, for example, if anything
we breed here at Aberystwyth suits say Natal, North America or Norway, and
if it does appear to do so at the first flush some plant disease — a rust form, say
— may quite decisively intervene. Exploration yes, and the bringing ol new
species and of new genes of tried species into every region, but the selection
and plant breeding must be conducted within the regions. What we want is
not a world-wide interchange of commercial seeds with their limited variability,
but a world-wide interchange of genes. It is probably nearer the truth to say
that there is hardly a region in the whole world that has yet got the best
combination of agriculturally useful genes in its grassland plants, while 1 make
bold to hazard the opinion that there are many regions in tin* world that have
not even yet got the right species to work. But of this again presently.

1 am sure of this, however, that a general world interchange of commercial
grassland seeds is bad for the grasslands of the world. It has admittedly done
good in the past, it was necessary in the opening np of new countries, but it has
also been responsible for a great deal of harm. I agree with Dr. Wilcox that
“ nations can live at home ” in all manner of respects, and in no respect are they
better advised so to do (and as far as possible) than in that of their grassland
seeds.

I have implied that the first necessity is to map and classify our grasslands,
and this is true the whole world over*

PRESIDENTIAL ADDRESS.

I regard this question of mapping of prime importance. We have mapped
the whole of Wales, and my first intention was to devote my Presidential
Address almost entirely to a detailed discussion of our methods — for I believe
they are good methods and as methods are applicable the world over. Our maps
are, however, on view at the exhibit, and I hope Mr. Davies, who has been
primarily responsible for the methods and the work, and myself, will have the
opportunities of explaining our aims and methods to those who are particularly
interested, both around the maps and out on the hills and fields.

So much for mapping. I shall now venture some remarks upon the general
problems of grassland, and all said and done, the basic problems are the same
the world over. Of necessity I shall have to be selective and I conceive it as
being my business to generalize, and as you will all have abundant opportunities
amongst yourselves for correcting me, 1 shall not be afraid of generalizing here
and there on insufficient evidence.

The outstanding feature of grassland is its complexity. It is impossible to
isolate the factors, and I doubt if it will lead us very far if we attempt unduly
to isolate the factors — on the farm and on the ranges all factors interact.
Hardly ever do we attempt to grow a single grassland species by itself.
I like to grow Loiiutn italicion by itself for winter keep, and we are here
experimenting with growing Phleum prutnw (our S. 48) in cultivated drills
for winter keep, but this is incidental, and cannot now be discussed. As all
of us grow at least 2 to 3, 4 or more species together to make a swaid,
competition always enters into the matter. And always, always, always
there is the grazing animal.

Soil, climate, grazing animal. Which of these three is the most important
factor ? Most emphatically the grazing animal ! Manure right, sow right and
manage the grazing animal ^wrong and you are nowhere. Without the grazing
animal there would be no grassland worthy of the name anywhere in the
world. Management is therefore the key to the solution of the whole grass-
land problem. The real point is this, that the animal makes for itself its own
grassland. It is because of this, that Lsay there are regions in the w^orld not
yet using the right species (apart from the right genes of the right species).
By management entirely alter the conditions, make good lime deficiency, make
good phosphatic, and if necessary poatssic deficiency, make conditions above every-
thing favourable for a leguminous plant ; make it possible to hold animals to
the ground, and then you can begin to consider introducing and maintaining
species hitherto unthought of.

I believe, and I say this is not lightly or without experience, that there
are many range areas in the world where it would pay best and where more
stock could be carried, and that stock in better health, if about three-quarters
or more of the area were let go wild and completely unstocked, and if real and
tremendous things were undertaken, on well-selected remaining areas. Tn effect,
that is what we are doing here on the Welsh hills, and we are successfully

it AGJttCtr&TOBAL JOVmAt 0* BRITISH GUIANA, {££, 1.

introducing proper grassland species, including, of course, wild white clover
(trifolium repens), where such species have never before gained a footing.
We talk about grass and grassland. No grassland is worthy o£ the name, and
indeed is hardly worth bothering with, unless a legume is at work. Find or
breed the right legume for every corner of the world and you have tolerably
good grassland in every corner of the world. Make the conditions suitable for
the legume and manage the sward, to favour the legume as well as to feed the
animal, and everything else will be easy — the battle will be won,

This is indeed a sweeping generalization, but prove me wrong who can,
for not nearly enough work has been done in exchanging legumes all over the
world, and in making conditions favourable for legumes or in breeding legumes,

So much for the geographical problem, as I gee it ; now for the domestic
problem, the problem that affects everybody. The domestic pioblem is clearly
threefold. Firstly, how to produce grass at those seasons of the year when
it is most urgently wanted ; secondly, how to use and to farm grass with a view
not merely to maintaining, but with a view always and progressively to increas-
ing soil fertility, and thodly , how to manage grass so tb^t the animal always
has offered to it young, rapidly growing and succulent grass of maximum
nutritive value.

The whole problem, I repeat, resolves itself into management. Each of
the above desiderata calls first and foremost for rotational treatment Rotation-
al treatment of a farm as a whole, and of individual fields Hot at ton in tune
and rotation m y>au>. The always doing ot something this month with a riew
to obtaining some definite result two or three months later. Always, too, the
need of the sward must rank as of an importance at least equal to the day -by -
day needs of the animal. By adopting a syAem ot rotational grazing —
intermittent with pioper periods “ on ” and proper periods “off”— the animal
can be given somewhere every day what it requires, and the swards need never
suffer. One further point, swards will recover from the most villainous of
malpractices if such malpractices are not too long continued, and ij they are
not put into operation at precisely the same tune of the yea i, year after year •
Hence the need for rotational management all over tiie farm. Incidentally,

I may here interject that I do not hold with using fields continuously as
pastures or continuously as hay meadows ; to do so is an offence against the
basal idea of rotation m tune For rotation in tune I regard as the most
fundamental of all grassland principles, and yet, and perhaps on most grasslands,
especially on the ranges and open hills, the management is essentially the
same month for month, year after year, for generation after generation.
Ridiculous folly indefinitely perpetrated in the end enforces a heavy but just
retribution, and all over the world millions of acres stand as doleful witness
of agricultural practices conducted on a faulty and undeviating time
schedule.

mmmmriAii kr>m ms.

So much in general with reference to my three desiderate, ; now for the
particular, and I will deal first with my No, 2 Soil Fertility, for in the last
resort on this do 41 grass when it is wanted ” and “ succulent and nutritious
grass 99 so largely depend.

I have said that to ensure |toil fertility wc need to marry our stock to the
soil, and the cheapest and most effective way to do this is to plough up all grass-
lands that will take the plough at regular intervals. Always before ploughing up
graze as hard as possible for some months, in order to impregnate the soil with
urine and excrement — with what Mr. Bruce Levy so aptly describes as “stock
nitrogen.” Having turned the sod over, apply lime, harrow in, and you will
have made and spread an admirable compost all over your field. Now do what
you like. Cash this fertility, or some of it, where you can in a corn
or other crop, or sow straight down to grass again and cash your
fertility in more luxuriant grass and build up yet more fertility.
I hold that permanent grass where it is possible and on all grounds reasonable to
plough is wrong in theory, wrong in fact, is uneconomic and ridiculous. Of
course, you cannot plough up all the permanent grass, grazings and ranges in the
whole world, but with the tractor and modem implements you can plough in all
manner of unheard-of places and under all manner of difficult conditions.
Manifestly it would be madness to plough up many types of range country, as
that would be to invite certain soil erosion, but such is far from true of all range
country. And suppose you can establish a thicker sod than ever before, and
establish it quickly, and in the non-erosion season. While with a view simply
to the introduction ot new species, it is often sufficient merely heavily to culti-
vate and scratch. Pray remember you can plough up and put straight down to
grass again perfectly well, and pray remembei also that the best top dressing of
all is that put on the soil itself at the time of sowing seeds (I am not now refer-
ring to applications of inorganic nitrogen applied to bring grass at some wanted
time). How often to plough up is a matter of circumstances and condition.
Once in 100 years is better than never ; once in twenty years better still, and
once in ten years often quite sufficient. Plough more frequently than once in
ten years and you begin to be scientific, progressive, and a farmer in very truth,
for then amongst other things you can begin to avail ytfurself ol the labours oi
the plant breeder, and if you do things properly you are going to build up
fertility at a prodigious pace You can farm on the basis of temporary leys of
from one to six or eight years’ duration, and produce productive grass at all those
times of the year that climatic conditions permit stock to graze out of doors.
The production of winter grass in telling quantity is, for example, a very real
project under the climatic conditions of this country.

In regard to “grass when it is wanbed” and “succulent and nutritious
grass ” I will be very brief, for I have already detained you far too long.

The production of short, succulent grass, and at times of the y^r when
most needed, is a refinement of pasture management that is applicable in all its
intricate complexity only to the true grassy-clovery swards of the more temperate

44 - AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 1.

regions — to the fields of our farm lands. It is to grass of this sort that I am
now explicitly referring — to grass in the main consisting of the well-tried
European species tolerant to and actually thriving best under well regulated
heavy grazing and heavy trampling, the species that call aloud for and prosper
exceedingly only when amply assured of stock nitrogen.

The production of short grass is then just a matter of rotational and
intensive grazing ; of intermittent grazing with heavy urination, followed by
adequate periods of rest. Once a year the plants must he allowed to grow away
to permit adequate root growth. The botanical composition of any more or less
permanent or long-duration sward will lie a function (almost a direct function)
of the times of the year it is grazed hardest, and of the times of the year it is
rested. If on any field these times are the same year after year, the number of
species will automatically become very restricted, and probably in the interest
of the ration and of seasonal spread-over will become much too restricted and
automatically less and less grass will be developed just when it is most needed.
If you proceed to accentuate this time factor by applying nitrogen
always at the same date, very soon yon will kill out the particular
species which respond best to nitrogen applied at that particular date — such
species or strains will be literally grazed to death So once ihore J say, never on
long-duration swards and on permanent pastures do the same things to the same
date programme on the same field for over two years in succession — rotation in
tune again ' It is often a very sound practice to adhere to a time schedule for
two or even three years in succession on short leys (leys ol up to three years’
duration) for when you have ruined such leys you plough them up. Hence one
of the outstanding advantages of short leys. Short leys are intended to do a
certain thing, and when they will do this thing no longer you plough them up —
and I daresay that is about the best of all rules for the management of the grass-
lands of our farms.

Short grass at different a> <! at all tmm of /hr gear, and especially at the
most difficult times — that is my last point, and I think the most important point
of all, and it is one that offers tremendous scope for detailed research.

There are two main avenues ol approach, the one by employing special
seeds mixtures designed in the main to cater for a particular and short period of
the year (once more the glory of comparatively short leys, and the justification
of the plant breeder), and the other so to manure and so to rest particular fields
that they do in fact have grass to offer at the particular date demanded by the
grazing schedule.

I will give two examples of special “ time ” seeds mixtures. At this Station
we advocate comparatively simple seeds mixtures, and we have achieved great
success with one consisting only of our Station bred leafy perennial rye-grass
(Loliwn perenne) (Dr. Jcnkin’s S. 23), rough-stalked meadow grass ( Poa tririalis )
and wild white clover {Tnjoliwn repent*). In some years the sward so produced
(as is common with L. perenne) tends to go short in July and August. We have

PRESIDENTIAL ADDRESS.

however found that another excellent simple mixture is one made up of our
Station bred meadow fescue (Festuca pratenws) (S. 53) ; Dr. Jenkin’s pasture-hay
timothy (. Phlemn pmtenw) (S. 48), and wild white clover ( T repens ) ; this gives
palatable and productive grazing all through the season, and in July and August
considerably outyields the L. pwenue mixture. A mixture consisting of our
Station bred Alopecurus pratensis (S. 5(5) ; our Station bred red fescue (Festuca
rubra) (S. 59), and wild white clover ( T . repen •<) remains wonderfully winter-
green and gives an unusual amount of leafage in late February and during
March — that is to cater for the winter.

As to resting for particular periods, I will take as my example the pro-
duction of winter grass in this country, for our climate permits of out-winter-
ing. We in this country are now drying spring and summer grass for the
winter, and I am inclined to say why not grow winter grass for the winter and
convert it in situ ? It can be done already, despite the fact that the plant
breeder has hardly begun to show his hand in this matter.

What is wanted is winter-green strains and then the plan is to rest the
fields completely as from about the middle of August or not later than towards
the eud of September. By the use of proper strains, resting at the right time
and properly manuring, we here at Aberystwyth have obtained grass in situ
available from Christinas to the end of March, with a crude protein content of
trom about 14 to as high as 20 per cent, of the dry matter. The yield per acre
of this sort of grass then available has on occasion exceeded 3,500 lb. of dry
matter. Thus with a range of fields a great deal of grass of high quality can
be made available all the winter. Much better winter grass, and more of it,
can be obtained trom young leys sown with the right strains than from per-
manent pastures.

In our experience much better winter grass is obtained by resting a
pasture which has been heavily grazed and saturated with stock nitrogen for
some time than from an aftermath. If aftermath is wanted for winter grass
such aftermath should not he allowed to grow straight on from after hay
harvest, but the field should be grazed heavily as soon as it will hold stock after
harvest, given a dose of 4 ‘ stock nitrogen ’’ in fact, and then put-up for winter
grass. At the time of putting up for winter grass we always dress with about
1 cwt. to the acre of nitro-chalk — as a supplement to stock nitrogen inorganic
nitrogen is invaluable.

I have rather daringly covered a very wide field, and I have (although
partly in the interest of brevity) most daringly generalized. I am sure you
will appreciate the fact that anything of truth or value that I may have been
able to say is due almost entirely to the untiring efforts and competency of my
colleagues, They do the work, I do the talking, i am afraid I have talked
almost solely around my own experiences and the work of my own* Station.
But nevertheless, and however unworthily expressed, I think I have said
enough Vo justify the belief that ell of us here present are engaged in the study

46 AGRICULTURAL JOURNAL OF BRITISH GUIANA. £tX, 1,

of a very great science ; oar concern is, however, much more than that 4 w®
are concerned also with a very great art, and more still, this oar enterprise is
of prime sociological significance and importance.

If the peoples of the world, and to a man, are indeed to be adequately fed
with fresh food of the highest quality, and balanced in every respect, then the
enormous acreage of the world that stands in grassland of every character,
and of no character at all, must be brought to play its full part. It is not only
grass itself that is so essential as a feed, hut it is the whole acreage under grass
that must be made to yield to more intensive treatment. To an ever-increasing
extent this acreage must be made to produce better and better grasB, and also
other necessary crops.

THE BOEING POINTS FOR REFRACTOMETRE TESTS

OF SUGAR-CANE.*

C. CAMERON,

Field Manager, Sugar Experiment Station
AND

H. B. SINGH,

Laboratory Assistant.

The Zeiss Ref ractometer has been adopted in British Qniana for the purpose
of testing sugar-cane fields prior to harvest, and of guiding the selection and
discarding of seedlings at the cane-breeding station. Under the latter
conditions it was soon found that while the co-efficient of correlation was
high between the brix of expressed juice and the total solids as determined
by refractometer readings on composite samples from borings made in the top,
middle and bottom thirds of the stalks, the absolute values did not correspond as
closely as was desirable. An investigation was therefore undertaken to determine
if there was any fixed point or points in the stalk which would yield a refrac-
tometer reading identical, or nearly so, with the true mean brix of the stalk.

The work was carried out on plant canes of three varieties (P.O.J. 287b,
Diamond 10 and D. 06/30) and in duplicate on each variety. The procedure
adopted was to select from the same field of any one variety, five stalks having
eleven internodes (joints), five having twelve internodes, five having thirteen
internodes, Ac., Ac. On arrival at the laboratory, the tops (cabbage) of the
stalks as far as the first joint below the point of attachment of the oldest green
leaf-sheath were discarded. Then for each batch of five stalks the internodes
were milled separately, i.e., the five topmost (second) joints together, the five
next joints together and so on until the bottom or older end of the stalks was
reached.

The per cent, total solids in juice for each batch of joints was determined,
and by noting the weight of the juice extracted it was possible to calculate a
weighted mean total solids for the whole stalk. All that was then necessary
was to note at which joint or joints the per cent, total solids corresponded with the
mean figure for the whole stalk. The results obtained are presented in Table I,

It will be seen that in stalks of all lengths from fifteen to twenty -four
internodeB (joints) and of all three varieties tested, the per cent, total solids
of the juice from the seventh or eighth joint below the point of attachment
of the lowest green leaf-sheath corresponds closely and consistently with the
mean total solids of all the juice from the stalk.

•Reprinted from Tropical Agriculture, Vol. XIV, No. 11, pp 313-310, 1937,

48 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 1.

In the case of the shorter (younger) stalks, having from eleven to
fourteen joints, the locatipn of the joint with the true mean total solids is some-
what higher up the stalk, />., at the fifth and sixth joint below the point of
attachment of the oldest green leaf -sheath.

In the longer (older) stalks a joint near the bottom of the stalk (about
the sixteenth to the eighteenth joint below the point of attachment of the
lowest green loaf-sheath) also tends to yield a juice whose total solids
corresponds with the mean for the whole stalk, but the exact joint cannot be
defined with as much accuracy as the higher one and does not appear to
occur at all in the younger stalks.

Table II shows a typical set of readings for two groups of five canes.
They show that the difference in total solids between the fifth and sixth
joints, or between the seventh and eighth joints is slight. Observers can there-
fore decide on a definite point (say the sixth joint for canes having from eleven
to fourteen joints and the eighth joint for canes having from fifteen to twenty-
four joints) and expect a reasonably high degree of accuracy in the results.

An investigation of this nature incidentally reveals what point of the cane
stalk has the highest solids content. It was found that as far as the* shorter
canes (11 to 14 joints) are concerned, this is located at the base whereas in canes
with longer stalks (15 to 24 joints) it tends to occur approximately in the middle
of the stalk.

TABLE I.

Loc vtjon of Jojvr* or Cv\l Hr \lk^ with it.k <l\t Toial Holid^ coiuiW’omhno
to Mi v\ Total Solii^ or Emjkl Hialk.

S'JALK or

Number of Joint Below the Poiut of Attachment of the Oldest Green
Leaf winch may be Boied to Secuie a Refractometer Reading
Corresponding to the Weighted Mean Solids of the Whole Stalk,

Joints

5.57

±0.10

do.

5.83

=±=0.15

do.

7.00

±0.25

do.

• ••

1 1 9

0.25

±0.68

do.

7.87

=*=0.28

do.

9 • 4

...

7.28

±0.33

do.

• • •

8.11

±0.53

do.

• • 9

7.75

±0.29

do.

• ••

7.89

±0.35

1G 7

±0.63

do.

• «

8.89

±0,46

15.5

±1.06

do.

7,85 .

±0.60

18.0

±0.62

do.

7.25

±0.42

16.3

±0.G1

do.

7.25

±0.76

17.0

±1.00

do.

*'*

8.14

±0.59

18.0 !

±1.17

THU BORING POINTS FOR REFR A CTOMETER TESTS OF SUGAR-CANE 49

TABLE II.

Two Tyhioal Series of Refhactometer RnimNfis,

Joint No.

Five 12- Joint Stalks of D. 06/30.

Five 21-Joint Stalks of Diamond 10,

Refrac-

tometer

Solids.

Total
Weight of
Juice from
5 Joints,
lb.

Total

Solids from
Juice,
lb.

Refrac-

tometer

Solids.

Total
Weight of
Juice from

5 Joints,
lb.

Total
Solids in
Juice,
lb.

This Interno

de was discar

ded with top

; 12.450
12.675

12 975
17.8(H)

18 000
18.4(H)
18.4(H)
14.025
14175
9.550
4,925

Total ~
153.375

(cabbage.)

ccni^xxx xodaioi : : : : : :

0.75

! i.oo

, 1.00

1.00

0.75

0.50

0.25

18.8

17.8

18.5

19.0

19.2

19.0

18.9

19.0

19.8

20.2

19.8

19.6

19.8

19.6

19.2

19.4

19.7

19.8

0.75

1.25

1.00

0.75

0.50

0.75

1.00

0.75

0.50

14.100
13.350
13.875
14.250
14.4(H)
14.400
23.750
18.9(H)
14.250

9.900

10.100

14.850

19.8(H)

14.700

14.850

14.700

9.600

9.700

1 9.850

9.900

Total —
8.50

Weighted ]
Mean |
( Refracto- i
i meter

1 Solids - .

I 18.04 ,

1 ___ 1

Total -

Total™

14.50

279 225

Weighted

Mean

Refracto-

meter

Solids =*

19.26

Summary.

An investigation to determine whst joint or joints in a sngar-cane stalk bad
a total solids content corresponding with the weighted mean total solids of the
entire stalk is described.

It is shown that under British Guiana conditions an accurate reading may

he obtained from the fifth or sixth joint below the point- of attachment of the

oldest green leaf-sheath in the case of canes having from eleven to fourteen
joints ; and the seventh or eighth joint in the case of canes having from* fifteen
to twenty-four joints.

AGRICULTURAL JOURNAL OR BRITISH GUIANA.

It is also shown that no corresponding joint with the mean total solids
occurs in the lower (older) portion of the Btalk of canes having from eleven to
eighteen joints, but that such may be fonnd in the canes having from nineteen
to twenty-four joints. The location of this joint is, however, more reliable to
fluctuation, and observers may better rely on the joint with the mean total solids
in the upper portion of the stalk.

Acknowledgments,

The writers are indebted to Mr. 0. Holman B. Williams, Agronomist in
charge of this Station, for his advice during the progress of the work and his
suggestions with regard to the presentation of the results.

COFFEE QUALITY

The task of elucidating the factors that govern coffee quality is beset with
difficulties. Good field husbandry and factory practice can contribute much in
giving the desired size, colour and evenness to the raw coffee ; the special
requirements of the roast are more difficult to attain, whereas little is known of
the conditions that make for the desired acidity, body and flavour of cofl’ee in
the cup. The main difficulty in correlating the liquoring properties of coffee is
that it has not been possible to define liquoring properties in chemical term?.
The personal equation of the taster also plays an important role, thus making it
difficult to standardize any coffee samples under consideration.

The scientific literature on the subject of coffee liquor is scanty and not
very helpful, as it usually gives no useful clues that may lead to direct methods
of investigating the true meaning of differences in the liquoring properties of
coffee. Such differences, which often vary greatly between neighbouring
estates, play a profound part in the economy of coffee production, more especially
in East Africa, where such a wide range of prices obtains. The necessity for
making some progress towards the solution of this intricate problem has now
become urgent.

The outlook for making early progress by studying the nutrition of the
coffee tree or by comparing bean analyses with unstandardized terms of liquor,
offers little promise. It is therefore pleasing to read an account of some head-
way in the matter of elucidating coffee quality that has been made by investiga-
tors in Brazil and Costa Rica. ' The purpose of this note is to draw social
attention to these coffee quality investigations and to discus*, their possible appli-
cation to the coffees of East Africa.

An account of certain Brazilian investigations dealing with the effect of
harvesting and factory methods on coffee quality may be summarized as follows: —

1. When cherries were allowed to dry slowly on the tree in normal, harsh,
or “Rio-flavoured" regions, the resultant coffee was harsh, whereas similar dry-
ing on the tree in recognized mild-flavoured areas gave a mild coffee. With such
slow drying of the cherry, the specific natural flavours are retained in the
properly prepared coffee,

* Reprinted from East African Agricultural Journal, Vol, III, i— September 1937

*" Recent Efforts for the Improvement of Brazilian Coffee”, in the Month} y'Bulletm of
Agricultural Science <£■ Practice, Int Inst, of Agric., Rome ; January 1937.

AGRICULTURAL JOURNAL OF BRITISH GUIANA*

[IX, 1.

2. It was found also that cherries from regions known as good gave a coffee
of mild beverage only when subjected to correct harvesting and factory treat-
ment This consists in the main of slow drying with constant stirring of
completely ripe-picked cherries such that no fermentation of the pulp occurs .
When such correct methods were neglected, and mixed stripped cherries, even
from regions famous for high quality, wore allowed to ferment in the pulp, the
resulting coffee was inferior in beverage. In the above two investigations it will
be noticed that the coffee was prepared by the normal Brazilian method of dry-
ing the coffee in the cherry and then decorticating.

3. Another investigation compared the quality ot coffee from different
sources, when prepared by pulping the cherries and then washing and drying the
beans. It was found that all samples pulped, from every region, always gave a
mild beverage. The control samples, which were not pulped but were allowed
to ferment in the cherry, gave a beverage with a disagreeable flavour varying
with the degree of fermentation that had taken place.

4. A further test in tracing the harsh or mild quality of coffee was carried
out by spraying cherries ot known poor quality, while on the tree, with a sugar
solution containing cherry yeasts which are normally associated with high
quality. It was found that there was a difference in the quality of the coffee
from the sprayed trees. The sprayed cherries never had the harsh or “ Rio ”
flavour.

5. The effect of inoculation with a more suitable micro-flora was tested by
adding the pulp of cherries from a plantation yielding mild coffee to fermenting
cherries from a plantation known for its “ Rio-flavoured ” products. It was
found that the resultant coffee had a pronounced mild flavour.

In the Costa Rica investigations, using the wet fermentation method of
preparation, it was found that when pulp from a superior quality coffee was
added to another fermenting pulped coff ee, the resultant beverage was of a higher
quality.

It had been thought that the harsh or “ Rio " flavour, characteristic of coffee
originating from certain defined regions in Brazil, was due to the nature of the
soil. The above investigations, carried out independently in Brazil and Costa
Rica, showed that by proper treatment it is possible to produce mild coffees in
the regions hitherto known for their hirsh coffees. It has been s)iown that
the nature of the fermentation and the resulting quality depend largely on the
specific yeasts that predominate in the micro-flora of the coffee cherry.

It is supposed that the products secreted by the organisms in the pulp have
a profound influence on the quality of the coffee bean, as the cell wall of the
latter is more or less permeable to secreted ferments. It is believed that the
yeasts secrete a ferment which penetrates the beans and provokes the mild
flavour, or else that they secrete something specific which inhibits the activities
of other less suitable organisms which are normally responsible for the harsh
“ Rio ” flavour.

COFFEE QUALITY

A survey of the predominant micro-flora, in good and bad plantations
respectively, showed which were the most beneficial, and pure cultures were
separated out. It has been shown that when such pure cultures of yeast
are added to previously sterilized cherries, the fermenting processes and also
the resulting flavour of the beverage are altered. The practical application of
this study lies in altering the micro-flora living on the cherry and thus forming
associations in which the beneficent yeasts of high quality coffee predominate.

It will be appreciated that the above-mentioned results, quoted by M.
Rogerio de Camargo of Brazil and Dr. ('. Ricardo of Costa Rica, offer a direct
line of approach for investigating variations of coffee quality in East Africa.
They appear to offer more promising lines of approach than bio-chemical studies
of the metabolism of coffee bushes and analyses of coffee beaus, when one con-
siders that analytical data need not necessarily explain the finer differences in the
liquor of samples of coffee. Again, field and factory trials involving inoculation
with the predominant micro-flora living on certain cherries or pulp are such that
they can be initiated in a simple manner. Then, if these tests show sign of
promise, they could be followed up with a field survey of the types associated
with good and bad liquor and pare cultures of beneficial micro-flora could be
separated out.

Lest the above investigations should lead to too optimistic views being held
about the possibilities in East Africa, it might be well to refer to some of the
major difficulties involved. In the first place, the woik dealt mainly with the
extremes of harsh 01 “ Rio-ilavom e<l ” coffee against Brazilian mild coffee,
whereas here we have to deal with differences of liquor within a series of mild
Arabica coffees. The Brazilian investigations again deal largely with coffee that
is stripped off the trees, dried and decorticated — it being found that pulped and
washed coffee always gave a milder flavour. However, work in Costa Rica has
shown that the addition of selected pulp can improve the quality even of coffee
prepared by the wet method, so that it may be found that fermentations produced
by various micro-flora may have an effect even with the East African mild series.

Those working on coffee in East Afrioa are indebted to the American work-
ers for thus indicating a possible direct line of approach in investigating the
quality of local coffee, aud it is to be followed up by the Kenya Coffee .Team
with the coming crop.

NOTES.

Bronze-Leaf Wilt Disease of the Cooonut Palm.— For many fears
past coconut palms in Trinidad have suffered from a disease to which the term
“ Bronze Leaf Wilt ” has been applied. The Department of Agriculture recently
published a bulletin prepared by F. M. Bain on this subject. Thousands
ot palms have died as a result of this trouble, and the position as regards
coconut growing is such that, with the exception ot estates situated on the more
favourable sandy coastal belt, large tncts of coconuts in many areas are
threatened with extinction within the next few years. This disease occurs in
British Guiana and is responsible for the loss of many trees on soils unsuitable in
regard to texture.

DESCRIPTION OF THE DISEASE.

The usual age at which trees die from the disease is fifteen to eighteen
years. The three lowest leaves of bearing palms, which usually appear quite
normal and healthy previously, are observed to have taken on a yellow and
bronze colouring, the colour proceeding from the tips ( of the leaflets backwards.
At the same time the tips of the next two or three leaves are seen to be yellow*
ing, the extent Qf discoloration increasing with increase in the age of the leaf.
The yellowing of the leaf extends up to still younger leaves, but long before
the youngest leaves show discoloration of any kind a rot sets in at the base and
in the folds on the leaflets of the central spear of leaves. The rot later extends
into the cabbage. This rot develops to a considerable degree before the central
spear of leaves changes colour, but in the later stages of the rot they wilt,
turning a dull greyish-brown colour and fall over at the base. Shedding of
nuts takes place at the same time or slightly in advance of the discoloration of
the leaves ; the youngest nuts being shed first. The oldest inflorescence on
the tree is seen to be changing to a brown colour, in some cases even before the
spathe has opened.

In some instances palms which have shed their nuts are to be seen with
healthy inflorescences. This occurs after an extended drought period and then
palms recover with the advent cf the rainy season. Such palms may be found
in situations where “ Bronze Loaf Wilt ” does not occur.

It will be seeu that the external symptoms of this disease are identical
with those of “ Red Ring”, which was shown by Nowell to be caused by the
nematode Aphetcnchus cocophlus.

SOIL STUDIES.

In 1928 Briton-Jones suggested that a soil factor is responsible for the
diseaset since both he and Nowell were unable to associate any organism with
the disease except as a secondary infeotion. Soil studies therefore formed the
basis of this investigation.

A general soil survey gave no definite correlation between soil type and
Incidence of the disease. Examination of soils from “ Wilt ” and “ Wilt*free ,f

NOTES.

areas for texture, organic matter, nitrogen, carbon : nitrogen ratio ami available
phosphate showed no marked differences. Generally speaking, the soils of the
good ooconnt areas show more available potash than those of the “ Wilt” areas,
but the difference was not sufficiently large or consistent to account in itseli for
the disease. Weekly fluctuations in soil moisture, soil niti ate and water table
were studied over a period of eight months, which included both wet and dry
seasons, but abnormally wet weather during this particular period detracted
from the value of the results. Further moisture determinations, however,
during more normal weather, gave indications of a greater conservation of
moiBture in the sub-soils of healthy areas than in the contrasted wilt areas.

Consideration of the physical conditions and allied water relationships of
the soil led to a classification of wilt soils which clarified the problem con-
siderably. Three types were recognised :

I. Surface soil is close textured aud overlies a sub-soil which is im-
pervious to water. Such a soil is subject to waterlogging during wet
periods and liable to dry out quickly in the surface soil during
periods of drought.

II. (a) Soil and sub-soil are opeu-textured and free-draining. This leads
to a relatively poor water supply during dry weather.

(b) Soil and sub-soil are compact and dry out quickly in times of
drought.

III. Friable top soil with an intolerant sub-soil layer.

ROOT STUDIES.

(a) Root system of trees in healthy area : root development in the
first foot was very great, many branch roots and feeding rootlets being
observed. The number of roots decreased graduallj in the second and third
feet but was still appreciable. In the lower depths to six feet there w ere still
roots to be found, the majority within a six-foot radius of the bole.

(b) Root system of trees on soils of Class I : root development in the first
foot was very good, many feeding rootlets being observed. In the second and
third feet, the development was generally good, but in some instances a few
rotting roots were observed near the bole of the tree. Below this layer the
soil was waterlogged and a mass of rotted roots was encountered.

(c) Root system of trees on soils of Class II : root development in this case
was observed to a depth usually about four feet. The numbers of main and
branch roots as well as feeding rootlets were much less than in the case with
trees growing in healthy areas. The depth of penetration was also much less.

(d) Root system of trees on soils of Class III : this class refers to soils of
the Princes Town Marl type. Root development is comparatively good until
the marl layer is reached. Very few roots penetrate mto this layer. Where
wilt oconrs the marl layer is usually at a depth of two or three feet. Where
the layer 4s deeper, wilt is apparently not very prevalent.

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[IX, t

LEAF ANALYSES.

Leaf samples Were collected for analysis to see whether any differences in
the nutrient status of plants growing on contrasted healthy and wilt areas
could be revealed. It was found that, in general, the nitrogen status of palms
in wilt areas tends to be higher, and the phosphate status lower, than for palms
in the healthy areas.

CAUSE OF THE DISEASE.

In considering the soil data, the physical nature of the soil was found to be
the most important factor. From general field observations, incidence of the
disease is most marked during period of drought, but measurements of the avail-
able soil moisture in the top two feet of contrasted healthy and wilt areas brought
out no differences sufficient to explain the disease. It appeared, therefore, that
any difference must occur in the soil below two feet. Root studies showed
differences in the plants grown in the various soil classes, and indicated that the
water relationships were such as to hinder root absorption at certain periods.
Previous to wilting, the palms show very tine vegetative growth, and this
explains their high nitrogen status, as found by leaf analyses.

The disease can now be explained on all three soil types ;

Class I Soils — Close textured surface soil overlying an impervious sub-soil,
At the beginning of the rains the trees increase their absorption of water and
nutrients, giving'good growth and a healthy appearance. As the rains increase the
impervious nature of the sub-soil causes a temporary water table to be formed. As
this water table rises the subsurface roots are submerged, and finally die
and rot. The surface roots, however, continue their absorptive function.
During the ensuing dry period the surface soil dries out rapidly, and roots in
this area can function at most very feebly. In the sub-soil, where there is
ample moisture, roots have been killed out and hence no absorption can take place.
The result is water deficiency in the plant, which, combined with the increased
transpiration during dry weather, causes “Bronze Leaf Wilt”. During its youth
there may be sufficient moisture all the year round to satisfy the requirements
of the tree, hence “supplies” on this area look promising.

Clas s II Soils — Surface soil and sub-soil open textured and free draining.
During rainy periods there is a constant supply of water, and absorption pro-
gresses favourably, but during a prolonged drought the soil dries out rapidly
to a great depth, and the water supply may be reduced to the wilting point.

Class III Sods — Friable topsoil with intolerant sub-soil layer. General con-
ditions are similar to those of Class I soils. Palms make exceptionally good growth
in the early years, but the root system is restricted by the intolerant layer and
a stage is reached where it cannot meet the nutrient requirements of the tree.

METHODS OF CONTROL.

Class I Sods -* *More efficient drainage, and trenching with organic material*
Would produce a more even supply of soil moisture throughout the year*
Where such treatment is uneconomic, a change of crop is recommended, sugar
cane being the most suitable substitute.

NOTES.

Cl axs II Soils — Where possible, irrigation should be practised, but
conservation of the soil moisture might be attained by trenching with pen
manure, husks and other organic matter. In view of the poor nutrient status of
these soils, the application of fertilizers, particularly potash, is recommended.

Class III Soils — The depth of the intolerant sub-soil layer is the controll-
ing factor, and no economic remedy can be suggested. Where coconuts are
not profitable another crop should be grown. D.W.D.

Rotenone Yielding Plants of South America. — A most interesting paper
on these plants by B. A. Krukoff and A. C. Smith has recently been published in the
American Journal of Botany (Vol. 24, No. 0, .'>711-587, November 1937). These
workers have had many opportunities of examining in the field the species of
Lonchocarpus, etc., from which the natives of different parts of South America
extract fish poisons, and some of which have recently acquired a commercial
value on account of their content of rotenone and other extractives which are
valuable as insecticides. As a result of their collections and observations they
have now been able to make an important contribution towards the correct
botanical determination of these plants, which have hitherto puzzled botanists
working only with Herbarium material. Owing to the facts that some of the
species of Lonchocarpus are seldom found in flower, that the species concerned
are much more numerous than was realised by early workers, and that consid-
erable variation may exist in leaf characters of the same species when the leaves
examined are from old or young portions of the same plant, or from plants grown
under different conditions, it has been impossible for systematists working with
scanty material to distinguish correctly the different species concerned.

In their paper, Krukoff and Smith describe one species of Derris, and nine
species of Lonchocarpus, including three new species which are described and
named, and two species, the vegetative features of which are described but which
in the absenoe of flowers cannot yet be named.

The cultivated barbasco or cube of the Amazon basin, known in recent
years as Lonchocarpus nicou (Aubl.) DC, has been recognised as differing from
the original plant described by Aublet on which the species was based, and has
been named L. atilis A. C. Smith, sp. Nov. The other important rotenone
yielding plant of this area, timbo, is Lonchoccupus urucu Killip and SmitJv

Of more immediate importance to this Colony is the recognition that the
Haiaris, recently considered also to be Lonchocarpus nicou and therefore con-
specific with the powerful poison plants of the Amazon basin, are in fact different
species, thus readily accounting for the fact that they have a very much lower
rotenone content than cube. The White Haiari, which is found throughout
British Guiana, has been named L. Marty nil A. C. Smith sp. Nov., and the
Black Haiari, which appears to be well distributed in both Surinam and this
Colony, is recognised as L. Chrysophyllus Kleinh., though it is possible that this
name may have to be revised when further flowering and fruiting material,
whloh is very rare in the oase of this species, has been found.

5S AGRICULTURAL JOURNAL Of BRITISH GUUXA.

Surinam and Curacao* — In the Times Trade and Engineering of December
1937, Dr. M. van Blankenstein writes an informative article on these Dutch
colonies in the Caribbean. Surinam is a part of the South American continent,
with British Guiana, French Guiana and Brazil at its boundaries. Except for the
narrow, populated strip along its coast it is coyered with jungle and savannah.

The soil of the populated area is fertile. In the interior many valuable
tropical woods are found. Gold deposits, which have been exploited more or less
successfully for many decades, are found in widely scattered parts of the land in
the form of veins in rocks or in the mud of creeks. The most important source
of income for the country is, at present, another mineral — namely, bauxite, raw
material for the manufacture of aluminium. High-grade iron-ore is also found
in Surinam. Rivers facilitate transport across the populated area, which, how-
ever, has only 150 miles of serviceable roads.

In the eighteenth century Surinam was a source of wealth for the Nether-
lands. The beautiful patrician houses bordering the canals of Amsterdam are
built with money derived more from Surinam than from the East Indies. There
was an old and exceedingly rich class of plantation owners in Surinam who had
immigrated during the seventeenth century. Their descendants are still in Suri-
nam, but by the beginning of the nineteenth century they had lost most of their
wealth and in many cases their plantations. The cultivation of cotton and sugar
was ruined, that of cotton coming to an end with the competition offered by
North America, while other agricultural activities languished after the abolition
of slavery in 1863, not so much because of the abolition itself as owing to the
bad management which lollowed it.

From this time onward Surinam has been struggling with a population
problem. The country is as large as Java ; but Java has now 45,000,000 inhabi-
tants while Surinam has only 165,000. There are many different races of people.
With the abolition of slavery, Chinese were imported as workmen. Many of them
remained in the country and today they constitute 1£ per cent, of the population
in the form of a middle-class. Later British-lndians were imported in great
numbers and many of them, too, have climbed up into the middle-class, but since
1918 British-Indnn labour has no longer been obtainable. Nevertheless the
British-lndians constitute 27 per cent, of the population. Of much importance
are the Javanese, who, when their contracts have expired, either return again to
their native country or receive a holding as small farmers in Surinam. They
already form 23 per cent, of the population and their number is increasing. The
majority of the people of Surinam is, therefore, Asiatic.

This large country with its small population has for many years cost
Holland more than 3,000,000 guilders a year in the shape of various contribu-
tions, and the revenues do not offset this expenditure. Many enterprises Which
have been started have turned out to be unsuccessful. How the old agricultural
prosperity collapsed has already been told. The cocoa-tree promised, at the
beginning of this century, new wealth to the country, but when everything was

NOTES.

t h riving ft devastating disease (Witch Broom) affected the trees and put an end
to all hope. Subsequently the banana promised to bring prosperity, lmt another
epidemic ol disease (Panama Disease) completely destroyed the plantations.

One failure followed after another and the country suffers from lack of
population. The beautiful wood in the forests cannot be systematically exploit-
ed ; the iron ore is not transportable ; and for balata there is little demand. The
gold, too, has brought with it many bitter disillusions. There is no better
characterisation of Surinam than as the land of great but economically unexploit-
able possibilities. Hopes are now focused once again upon banana cultivation
and upon the export of citrus fruits which thrive well in this country.

Although “ negro-English,” the language of the slaves, is still the language
of the lower classes and the “ lingua franca ” of the islands, the whole popula-
tion and even the Negro and Red Indian children are educated in the Dutcjh
langnage. Education is compulsory and the primary language employed by
schools is Dutch. The non- Asiatic population is chiefly of the Protestant religion.

The Antilles.

The Antilles, a group of islands with Curacao as the main unit, offer a
great contrast in all respects to Surinam. The earth is barren, water is scarce,
and there are no mineral deposits. The native language is Papiamento, a
Spanish dialect. The population is Roman Catholic. There has been no im-
portation of Asiatic peoples worth mentioning. Since the conquest of the
island from the Spanish in 1636, Curacao has remained Dutch territory. Like
Surinam, the colony was long poor, and only less expensive to the Motherland
because of its smaller population and smaller area, but when the Shell and
Standard Oil groups established there their great refineries for Venezuelan oil,
a period of prosperity began for Curacao. Even the great world economic crisis
could not affect it seriously. It is Curacao’s advantageous position in relation
to the Panama Canal which has made this development possible. Curacao
eclipses Amsterdam many times in the volume of shipping directed to the port,
and in terms of tonnage Curacao is now the second seaport in the Dutch Empire.
The oil industry and shipping maintain the entire population. The colony is no
longer cause for budget worries.

Both the West Indian Colonies belonging to the Kingdom of the Nether-
lands have, therefore, their tradition. The Dutch people have become accus-
tomed to spend with inexhaustible resignation a great deal of money on Surinam,
poor but nationally closely connected with Holland, and to hear of nothing but
prosperity in, connexion with Curacao.

Soil firOftion,—- The following are two extracts from a recent article by Sir
Frank Stock dale, K.O.M.G., K.B.E., in the Emp. Jour. Exptl. Agr. } October, 1937,
on the problem of soil erosion : —

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[IX, 1.

West Indian Dependencies.

Very little attention has been given to soil erosion in these dependencies
and generally speaking the loss of soil from this cause has not been as excessive
as it has been elsewhere, mainly because clean weeding has never been adopted
as an agricultural practice, and planting in holes has been general. Sugar-cane
is planted in holes or furrows, and in the cultivation of many food crops the
system of preparing holes and mounds is fairly common. In some of the
mountainous islands with heavy rainfall, erosion has, however, been serious, and
it has recently been recognised, in St, Vincent for example, that considerable
erosion is taking place. In Jamaica, moreover, the position is serious in the
Blue Mountain range, and has not received the attention it deserves. It is,
indeed, fortunate that the calcareous soils ot Jamaica do not erode readily as
little or no attempt is made to check erosion, but the soils in the Blue Mountain
range area derived from schists are easily erodibie, whilst uncontrolled
deforestation has been permitted to proceed too far in the island.

In St. Vincent, soil erosion can be really serious, and one or two small-
holding settlement schemes have, in the Cumberland Valley of that island, been
established on lands situate on hill slopes which slioujd have been kept in
permanent forest cover. The condition ot these small-holders, after some years
on land of inferiors quality subject to continued erosion can well be imagined,
and it is to be hoped that in all future settlement schemes attention will be given
to the selection of land of good average quality, and that no scheme be started
until a satisfactory report on the land has been obtained from the Department
of Agriculture. In St. Lucia, attention has recently been called by Mr.
Wimbush, in his report on the forestry position in the Windward and Leeward
Islands, to the unsuitability from the stand-point of erodibility of certain
lands recently selected for development, and a re-consideration of the project
has resulted in a revision of the proposals.

In Trinidad, the Imperial College of Tropical Agriculture is studying the
amount of erosion on certain soil types in connexion with investigations relating
to shifting cultivation.

More attention should, however, bo directed to the question of soil erosion
in all the wetter and more mountainous islands in the West Indies, and all
Colonial Agricultural Scholars should, whilst at the Imperial College of Tropical
Agriculture, have their attention specially directed to the question.

General Conclusions.

An attempt has been made to survey the present position in regard to
soil erosion in the Colonial Empire, to describe the measures which are being
taken to check and control its effects and to indicate where further efforts are
required.

The most serious losses are taking place in East Africa, particularly in
Kenya. Here the condition of some of the Native Reserves is becoming serious
and deterioration is proceeding apace* It is the most important land problem
which the country has to face, but if active steps are taken without delay the

NOTES.

position can be greatly improved within a decade. The actual causes of erosion
are numerous and varied, and each drainage area of any country requires close
examination before plans of reconditioning or control are decided upon.
Untutored agricultural operations are responsible for erosion in many parts,
whilst in others concentrations cf stock numbers due to a shortage of grazing
or inadequate water supplies are the chief contributory causes. In yet others,
stock numbers are in excess of the carrying capacity of the land and overgrazing
takes place. Rotational or deferred grazing has been demonstrated to be
effective as a cure in certain circumstances, and strip-cropping, contour-ridging,
and mulching have proved their value in agricultural lands. There are many
instances where deforestation has been excessive, and considerable areas of land
may have to be retired from cultivation or grazing if the position is to be
improved.

The problem is one which must be approached from various angles. Physical,
biological and social factors have to be considered, and there is no doubt that the
fullest co-operation between the administrative and technical departments is
essential if advances are to be made. Generalizations as to control measures
must be avoided. Each area should be examined in detail and working plans
evolved before any decision is taken as to how the problem should be tackled.

Vegetation-control is the most important method of controlling soil erosion,
since it produces a cure by natural methods and is much less expensive than
treatment by mechanical means. In cultivated lands on hilly slopes, however,
the use of contour-ridges, tei races, hedges and drains is necessary when strip-
cropping cannot be adopted, if the tortile top soil is to be saved.

The uso of control measures, without an improvement in the systems of
agriculture and animal husbandry, is likely to be unsatisfactory. Buck a policy
meets only the circumstances of the present and does not provide for the future.
Expenditure on anti-erosion measures should at least be matched with expendi-
ture of a similar magnitude for agricultuial education, demonstration and
propaganda, it the future is to be secured.

Clarification of Sugar Syrups.— -In the December 18, 1937 number of Chem-
istry and Industry, A. Nagaraja Ran and B. B. Gupta published the following
letter on this subject : —

Considerable difficultly is being experienced in the preparation ot cOftcen-
trated, clear and brilliant syrups from most of the sugars manufactured in India.
Repeated treatment with large amounts oi activated carbons, followed by more
than one filtration, has boen found to solve the problem partially. It is,
however, still believed that the syrups made from imported sugars are far more
satisfactory. #

The manufacture of concentrated, clear and colourless sugar syrups is of
great industrial importance and the utilization of Indian sugars (even the lower
grades) for this purpose has been investigated in this laboratory for some^ time.
We are glad to report that a new method developed by us has been found to be
very satisfactory.

AGRICULTURAL JOURNAL OF BRITISH GUIANA,

[IX, t

The syfu p is treated with jtwt the minimum quantity of sodium alumin&te
and activated carbon and then a current of carbon dioxide is passed through it to
saturation. After allowing the mixture to stand for some time (about 15
minutes), the mixture of aluminium hydroxide and active carbon is removed by
filtration to obtain a satisfactory syrup. It would not be out of place to mention
here that the application of similar methods is being tried by us, also for the
clarification of the different products in the various stages of the sugar industry,

Aluminium hydroxide has already been employed before for similar
purposes by others, but there is always a definite advantage gained^iu the
method indicated above over the others, in that here the amount of aluminium
left over iu the filtrate (syrup) has been reduced to the minimum. Besides, in
this method the active aluminium hydroxide is generated in situ and well
mixed up with the active carbon thereby enhancing its decolorization property
also.

Legislation* — The following have been appointed Inspectors in the terms of
Section 19 of the Plant Diseases and Pests (Prevention) Ordinance, 1935 : —

The Director of Agriculture

The Deputy Director of Agriculture '

The Entomologist

The Botanist and Plant Pathologist

All Agricultural Superintendents, Assistant Agricultural Superintend-
ents and Agricultural Instructors.

Technical Assistants to the Entomologist and Botanist.

An Ordinance to provide for the control of Sugar Experiment Stations for
a period of five years from the first of January, 1938, has recently been passed.

In accordance with Section 3(1) and (3) of the Animals Diseases Ordinance,
1936, the following list of Registered Veterinary Surgeons was recently
published for general information.

Name

Date of
Registration

Address.

Benjamin, Charles Bishop
Bruce, Samuel Nathaniel, D V M
Fraser, Hugh Arthiu, B V.Sc,

Fulton, Andiew MePheison, D.V H.,
M,R C. V.S.

Hanaro i, James

Kerry, Robert Retna

Khan, Eli Raksh ... r

Larrouv, Francis Isaaore

Mitchell, Henrv Alfred

Bone, Thomas, O.B.E., M.R (\V S

27.10. am
16. 4.1020
12. 9 1933

Plaisance, E C„ Domerara
127, Laluni Street, Georgetown.

5, David Street, Kitty, E.C., Demerara.

5, 7.1924
27.lO.UKKi
27.10.1909
27 10.1909
26.* 5.1909
20. 8.1909
19 91928

Vryheid’s Lust, E.C., Demerara.

Agricola Village, E.B., Demerara
Peter’s Hall, E.B., Demerara.

Public Hospital, Georgetown.

Messrs. Brodie & Rainer, Georgetown.

31, Camp Street, Georgetown.
Department of Agriculture, Georgetown,

JA * —

REVIEW.

The Practical Atpeeh of Copra Deterioration : by F. C. Cooke. Bulletin No.

28, General Series, Department of Agriculture, Kuala Lumpur, F.M.S. 49

pp. Price 50c.

The author is to be congratulated on a bulletin which should be of
the greatest value to copra producers. Like good copra, it is clear and com-
pact, free from the excess moisture of verbosity and the disfiguring mould of
unnecessary technicality. Although the basis of the work is essentially chemi-
cal, only the practical applications and arguments are shown, and these make
straightforward reading. Any attempt to summarize the bulletin would be
futile, since it is in itself a summary, and its range can be seen from the section
headings given below.

Part 1. bitrodintion : moisture content and quality : the range of quality :
the marketing of copra • conclusions.

Part II. Copra Deterioration : review of previous literature : the charac-
teristics of deterioration : agents ot deterioration : deterioration due to moistuie :
deterioration due to smoke and heat : the production of ’* smalls ”, fractures and
dust : variations in the oil content

Part III. The Pi event am ol Deterioration : analysis of the causes of
deterioration : the prevention of deterioration — pre-treatment of nuts, copra
drying, after-treatment of copra.

Part IV. Copra Griuhni/ field and laboratory grading : commercial
grading.

Not a word is wasted, and for that reason it requires- careful study, but the
time and effort will be well spent.

D.W.D.

MINUTES OF THE FIFTEENTH MEETING OF THE BRITISH
GUIANA BEEKEEPERS’ ASSOCIATION HELD AT THE
HEAD OFFICE, DEPARTMENT OF AGRICULTURE,
GEORGETOWN, ON MONDAY, JANUARY 24.

PRESENT.

Mr. E. A. Borman, .... President (in tho chair)

Prof. J. S. Dash (Director of Agriculture),

Messrs. E. S. Vieira, C. A. Quail, M. P. Correia,

D. M. Khan, Robert Williams. E. S. Christiani, Jr.,

D A. Iloo, W. M. A.Roberts, M. J. Henriques, , _

.7. G. Martin, 0. C. Dowding, K. W. Ferdinand, H. "" Member*.

Cliand, H. Madramootoo, G. W. Roberts, N. A.

Rickford, A. Hn-a-Kam, Mrs. I. Tjon-a-Man and
Miss H. L. Ferdinand

' with

Mr. H. D. Huggins .... Secretary.

Excuses for their absence were received from Messrs. J. W. Perry, J, C*
DaSilva, J. A. Trotinan, Mohamed Ishak, W. Humphreys, D. A. Pile, K.C. Hose,
P. A. Iloo and S. A. King.

Minutes.

The Minutes of the previous meeting held on Monday, July 2fi, 1037, were
read, and on a motion by Mr. C. A, Quail, seconded by Mr. E. S. Vieira, were
confirmed.

Fixing . the price op Honey.

Referring to the minutes, Mr. Henriques asked what action was being
taken in regard to the fixing of honey prices. The general opinion was that
the most expedient step was to appoint a standing committee, as the Director of
Agriculture had i>reviously suggested, to report on what action should be taken
from time to time. After some discussion it was agreed that the President, the
three Vice-Presidents with Mr. Henriques and Mr. Huggins be appointed to form
the Committee.

Election of Office-bearers.

On a motion moved by Mr. Henriques and seconded by Mr. J. G. Martin,
the following members were elected to the Executive Committee for 1938 : —

His Excellency the Governor .... Patron

Mr. E. A. Borman .... .... President

MINUTES OF THE B. O. BEEKEKPEBS’ ASSOCIATION.

Mr. W. M. A. Roberts
Mr. C. A. Quail
Mr. 8. A. King
Mr. R. B. Hunter |

Mr. D. A. Iloo l
Mr. A. M. Fulton J
Director of Agriculture
Mr. H. D. Huggins ....

Vice-President

Vfcco-President

Members of Committee

Ex-oilicio Member
Secretary -Treasurer

On behalf of those elected the President thanked the members and gave
the assurance that an ettort would be made to maintain the useful services of
the Association during the year that was ahead.

llm Excellency the Governor to be asked to be Patron.

It was decided that His Excellency the Governor, Sir Wilfrid Jackson,
K.C.M.G., should bo asked to become Patron of the Association, which honour
his predecessors had been pleased to confer on the Association.

Secretary’s Report.

The Secretary's Report was then read.

Referring to the report, Mr. Ilenriques suggested that more advertising
should be undertaken.

The Director of Agriculture drew attention to the considerable variation in
honey crops. He pointed out that both consumption and production had gone
up and that, ii beekeepers wanted to be assured that production would at all
times keep pace with demand, the supply of nectar plants should be increased.
He was pleased to see lady members present and he hoped the indication was that
interest in the movement was spreading. He was of opinion that \illage
organisations might, with advantage, make beekeeping discussions with practical
demonstration one of the phases of their activities. He mentioned that although
the demand was not great there were at intervals enquiries for section honey.

Mr. D. A. Iloo drew attention to the fact that the Department had en-
couraged the distribution of honey plants by ottering special prizes.

Mr. Dowdiug reminded members that the value of bees could not be
estimated only from honey sales but the great service they did in regard to
pollination and setting of fruit was important.

Mr. Borman mentioned that the village movement idea was an excellent
one aud he wab already playing his part, since, on more than one occasion, he
had given short talks to village organisations.

The Director of Agriculture suggested that a permanent advertising dis-
play, say in a grocery, was worth considering.

Mr. Iloo moved the adoption of the report and Mr. Vieira seconded*

66 ■ ' AGRICULTURAL JOURNAL OF BRITISH GUIANA. [ISC, t

Honey Display at the Berbice County Agricultural Exhibition.

The next item considered was the exhibition to be held in Berbice. After
some discussion it was agreed that the Executive Committee should meet to
discuss the space available and type of exhibit to be prepared for display at the
forthcoming County Agricultural Exhibition to be held in Berbice.

The Director of Agriculture suggested that it might be -arranged at some
future meeting to have one or two papers presented by some of the more
experienced beekeepers. Mr, Iloo agreed that this would be a good idea and was
of opinion that his brother Mr. F. A. Iloo, would be willing to contribute one.
Other names suggested were Mr. E. A. Borman, Mr. K. B. Hunter, Mr. L. D.
Cleare and Mr. H. W. B. Moore.

The view was also expressed that it would be a pity if at ordinary meetings
members, especially younger members, should refrain from expressing their
opinions on subjects raised for discussion.

More than one member stated that beekeepers on the whole would be glad
if it were possible for more beekeeping extension work to be done by the
Department of Agriculture. There were many beginners for whom helpful
attention was desirable.

Mr. Henriques suggested that the Association might approach (Government
with the object of obtaining a loan for the purpose of establishing the industry
on a more extensive basis.

In regard to extension work, the Director ot Agriculture mentioned that
during the week of the County Agricultural Exhibition, Mr. Huggins would be
in Berbice and it could probably be arranged for him to discuss their difficulties
with the Berbice beekeepers.

The President read his report. He was thanked for his excellent summary
of the year’s activities and achievements, arid the Director of Agriculture
moved that the report be placed on reoord. Mr. C. A. Quail seconded.

Appreciation was expressed by the President and others for the interest
taken by Mr. R. Williams of Rosehall, Corentyne, Berbice, and Mr. D. M. Khan
of West Coast, Berbice, in being present that afternoon.

At this Stage Mr. Henriques proposed Messrs. Z. D’ Andrade and L. 0.
fcimith as members.

The Chairman then thanked members for attending and the meeting
to. a close.

NEWS

A meeting of the Board of AgrionUnre was held on January 4 mainly
to discuss the plaintain export trade and the Cattle Branding Ordinance.

The British Quiana Beekeepers’ Association held its Annual General
Meeting on January 24. Minutes of this meeting are published elsewhere in
this Journal.

The Director and the Deputy Director, accompanied by the Agricultural
Superintendent of the District, visited the experimental banana plot at Middlesex
and the Toevlugt Farm Unit on January 1 3. The Deputy Director visited these
trials on several occasions during the period under review. The Plant Patho-
logist visited the banana plot on January 11 and began spraying operations with
Bordeaux mixture as a control against Leaf Spot and Panama Diseases.

The Deputy Director also visited Esseqnibo: East Coast, Demerara and
Berbice.

The Director of Agriculture and the Hon. C R. Jacob left the Colony on
January 20 for Surinam on a special mission to make a study of the situation in
regard to the coffee industry and the recently organised Surinam Central Coffee
Board.

On the Director’s return on February 5 he proceeded to Trinidad to
represent British Guiana at the Conference of the British West Indian Fruit and
.Vegetable Council held from February 9 to 15. During the Director’s absence
Capt. F. Burnett. Deputy Director, was appointed to act.

Mr. 0. C Dowding, Agricultural Instructor, resumed duty after leave of
absence on December 8.

The Secretary of State for the Colonies has been pleased to approve of -the
appointment of Mr. C. H. B. Williams, M.A., A.I.C.T.A., Dip. Agr., Cane
Agronomist, to the post of Sugar Agronomist and Plant Breeder as from
January 1, 1938.

Consequent on the appointment of Mr. E. M. Morgan as Assistant Agricul-
tural Superintendent, Mr. H. A. Cole, Agricultural Instructor, has been promoted
to the Senior Grade.

Mr. I. Dewar has been appointed to act as an Agricultural Instructorfrom
February 1,

•68 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 1.

A Conference of the District Staff and Headquarters Officers concerned
was held on January 20 and 21 and was presided over by the Deputy Director ;
the various programmes of district work and experiments to be carried oat
during 1038 were discussed.

Livestock importations by the Department during recent months have
included:

Cattle. (Immunised against tick-borne diseases)

5 bulls and 3 heifers (Red Poll)

2 bulls and 3 heifers (Hereford)

Pigs.

2 gilts and 1 boar (Canadian Berkshire)

Poultry.

2 cockerels and 8 pullets (Barred Rocks)

Among recent visitors to the Department were the Hon. E. J. Waddington,
C.M.G., Colonial Secretary ; Prof. F. Hardy and Messrs. B. N. Ray and 0. F.
Churaman, from the Imperial College of Tropical Agriculture: Mr, J. J, Ochse.
from Surinam; Monsieur Montayne, Dutch Consul General in New York; Mr. A.
Wanford, of the Employers’ Liability Assurance Corporation, Ltd., London ;
Mr. W. D. Lambie, His Majesty’s Trade Commissioner for the West Indies ;
Mr. M. B. Palmer, Canadian Government Trade Commissioner and Mr.
Edward J. King, M.C., Secretary of the British Empire Producers’ Organization.

His Majesty the King has been pleased to appoint the Honourable E. .T.
Waddington, C.M.G., to be Governor of Barbados. Mr. Waddington, who was
Colonial Secretary of this Colony since September 20, 1113.'), has always evinced
the keenest interest in matters connected with the agricultural progress of the
Colony.

As we go to press, news has been received that the Hon. G. D.Owen.C.M.G.,
Colonial Secretary of Barbados, has been appointed Colonial Secretary of British
Guiana vice Mr. Waddington. Mr. Owen has formerly served in British Guiana
from February 13, 1925 to September 3. 1931.

PLANT AND SEED IMPORTATION.

Introdaotions by the Department of Agriculture for the period
November, 1937— February, 1938.

Name

Quantity.

Whence Supplied

Economic.

Derria fUiptiea

cuttings

Puerto Rico Agrl. Expt. Stn.,
Mayaguez, Puerto Rico.

Tepkroftiu toxica via

seed

do.

Cracca ( Tephrosia ) cogel Hi

seed

do.

Tree Tomato— Ct/phomandra hetacea

1 ox

East African Agrl. Research
Stn., Amani, Tanganyika.

Tobacco Seed— Gold Dollar Strain 8

2 oz.

Coker Pedigreed Seed Co,
Hartfiville. S.C.

Lentils— Types 11 and 47, Hybrid |
111-86.

1 oz each

Botanical Sub Station, Imp.
Dept of Agriculture iu In-
dia. Puna.

Peas— S. 21) and A-15

do.

Assorted Vegetable Seeds

20 lb

Messrs. P. Henderson & Co.,
New York.

Ornamental ,

Flovvei SeedH— Assorted (

182 pkts.

| do

Poses— Double White Killarney

2 plants

j do.

Hoses ,0 varieties

8 plants

Messrs. H. G. Hastings, U.S.A.

Poses 10 varieties

24 plants

Messrs. Benjamin R. Cant &
Sons, Colchester. England.

A macaw t ere/ ho

1 plant

Messrs, G. Reuthe, Ltd.,
Keston, Kent, England

Lonicera Uddeln and i ana

1 plant

do.

Thnt/a oriental is 1

1 plant

do.

DendrocaUumi* ^ti ictus

2 plants

Puerto Rico Agrl. Expt. Stn..
Mayaguez, Puerto nioo.

Ha i a m out i a grandi ft ora 1

2 plants

do.

(tlirt/cidiasejnum

10 cuttings

do.

Phaeomn ia * periom j

1 plant |

do.

Vanilla plan if cilia

2 cuttings J

do.

METEOROLOGICAL DATA, 1937.

BOTANIC GARDENS, GEORGETOWN.

1937

Months

Rainfall,

Inches

Number of Days of

Bain

Evapora*

tion,

Inches

Under !
.10 in. j

f .10 in.
to

.50 in.

.50 in.
to

1.00 in.

A «

*-» Ol

Above
2.00 in.

Total

Days

Janaary

11.41

1 2

4.01

February

.95

5.08

March

1.26

...

5.88

April

5.44

1 1

...

5.51

May

12.43

8 j

...

1 4.23

Jane

17.80

3.76

July

15.63

i 2

3.88

August

7.22

• M

4.60

September

3.16

• . ■

5.69

October

3.10

• • ■

5.44

November

4.10

1 1

i 1

...

4.76

December

9.66

6 !

! 6

l 3

3.12

Totals

| 92.16

j 87

1 20

199

55.96

AIR TEMPERATURE AND HUMIDITY IN THE SHADE.

BOTANIC GARDENS, GEORGETOWN.

Air Temperature 1

Hnmidity

Mean

Months

Maximum

Minimum

Mean

January

83.6

76.0

79.8

84.7

February

84.5

75.7

80.1

77.9

March

85.0

76.5

80.7

77.2

April

85.5

76 3

80.9

78.8

May

84.5

76.9

80.7

83.9

June

84.9

75.6

80.2

85.7

July

84.8

1 75.1

79.9

84.7

August

86.1

75.8

80.9

83.5

September

88.2

76.4

82.3

79.8

October

88.9

76.5

82.7

79.G

November

84.3

76.7

80.5

81.5

December

86.1

76.2

81.1

82.2

Mean

85.5

76.1

80.8

81.6

WETTEST AND HOTTEST DAYS AT VARIOUS STATIONS.

Stations

Wettest

Days

Rainfall,

Inches

Hottest

Days

Temper-

ature

in shade °F

Botanic Oardens,
Georgetown

^ June 19th

3.14

Sept. 9th

92.5

New Amsterdam,
Public Gardens

July 2.nh

3.48

Sept. 8th &
Oct. 23rd

j 94.0

Ouderneeming Indus-
trial School, Essequibo

Jan. 6th

3.60

Dec. 8th

93.0

Hosororo,

N.W.D.

Dec. 24 th

~ - I

3.38

Sept. 9th

i 94.0

CURRENT PRICES OF COLONIAL PRODUCE

From The Commercial Review , Journal of the Georgetown Chamber
of Commerce , Vol. XXL ', No, 2 , Tuesday, 28th February, 1938.

SUGAR.

Per 100 lb. net 3 lb. per Bag allowed for tare

Dark Crystals for Local Consumption $3.30

Yellow Crystals do. do $4.00

White Crystals $4.75

Molasses Sugar none offering.

Above Prices include Excise Tax of 90c.

RUM.

Imperial Gallon. CaBk included.

Coloured, in Puncheons — 40 to 42 O.P...(for export). ..60c.; Hhds. 52c„ Barrels 77c

White, in Hogsheads— 40 to 45 O.P...(for local consumption) 45 to 55c

MOLASSES.

Per Imperial Gallon. Naked.

Yellow (firsts) 10c.

Yellow (seconds)...! 5^c.

RICE.

Rice per Bag of 130 lb. gross. Brown Super $3.30 to $4.00 ; No. 1, $3.60 —

$3.75 ; White, None available. Lower Grades $2.75 — $3.00 as to quality
Padi per Bag of 143 lb. gross, $1.00 to $1.50 as to quality.

GENERAL.

Gold, Raw average per oz. $26 to $27.

Diamonds, — pro rata as to quality average per carat $10 to $11.

Timber, Greenheart, (Lower grade measurements). ..40c. to 60c. per c. ft. ;

for export 72c. to $1.00 perc. ft.

do. Railroad Sleepers — (Mora) $1.68 each.

Greenheart Lumber $70 to $80 per 1,000 feet.

Crab wood Lumber $60 to $75 per 1,000 feet.

Shingles, Wallaba, 4 x 20 and 5 x 22 inches $4.50 to $6.00 per M.

Charcoal, Capped for shipment 72c. to 85c. per bag.

Firewood $2.50 per ton.

Coconuts... Selects, $9.00, culls $6.00 per M... Copra $1.75 per 100 lb. prime Copra,

Balata Venezuelan, none. Local Sheet.. .36c. to 38c. per lb.

Cocoa 19c. to 19ic. „ „

Coffee ! 5c. to 5jc. „ ,,

N.B.— Duty Payable on value at time of Importation and rate of exchange on day of
arrival.

Vol. IX, No. a.

June, 1938.

The

Agricultural Journal

British Guiana

I5S03

PUBLISrfCD BY

THE DEPARTMENT OF AGRICULTURE,

GEORGETOWN. BRITISH GUIANA

Price

• ■
• 1

•»

• a
M

. 6d.

DEPARTMENT OF AGRICULTURE.

ADMINISTRATION

Director of Agriculture
Deputy Director

Clerical

Senior Clerk
Registrar of Banks

Class III Clerks

Probationers

Librarian

RESEARCH BRANCH.

Botany and Plant Pathology

Botanist-Plant Pathologist and Superintend -
ent. Botanic Gardens :

E. B. Martyn f B A., AXC.T.A.

Technical Assistant :

N. Persaud

Chemistry

Chemist :

D, W. Dufchie, M,A , B.Sc., Ph.D , FXC,
Assistant Chemist :

C. L. C. Bourne

Entomology

Entomologist :

L. D. Clear©, F.R. Ent. 8. (ou leave)
Technical Assistant :

C. Williams

Rico

Assistant Plant Breeder :

P. A. Chan-Choong, B.Sc , A.I.C T.A.

Sugar

(In co-operation with the Sugar Producers)
Sugar Agronomist and Plant Breed* r :

C. H. B. Williams, M.A., A.I.C.T.A., Dip.
Agr. (on leave)

Laboratory Assistants ;

H. B. Singh

A, V. Wan-Ping, Dip. Agr,

Statistical Clerk ;

J. B. Bourne

Prof. The Hon. J. Sydney Dash,

B.Sc. (Agnc.)

... F. Burnett, M.C., M.A,

Staff.

... J. F. Irving, M.C.

W. G. Delph
( A. A. Thorne
] Miss N. Green
( Miss D, M. Terrill
Miss M. Cheong
P. 0. Jackson
S. A. Adams
Miss B. Delph

Miss V. Ohan-Choong (on leave)

LIVESTOCK BRANCH

Veterinary Surgeon :

T. Bone, O.B.E., M.B.C.Y.S. (on leave)

H A Fraser, B.V. Sc. (acting)

FIELD BRANCH

Agricultural Superintendents:

Berbice— J. D. Gillespie, B.Sc.

Demerara, East— E. M. Peterkin
Demorara, East Bank — H. D. Huggins,
M.Sc., Dip. Agr.

Demerara, West— E. G. Benson, B.Sc .

A.I.C.T.A., Dip. Agr.
Essequibo-A. A. Abraham
Assistant Agricultural Superintendent :

Berbice— E. M. Morgan
Agricultural Instructors :

Botanic Gardens — H. A. Cole

fC C. Dowdmg, F.L.S.,
Demerara, East—] F.B.H.S.

IW. A. Bo veil.

Demorai a. East Bank— I. Dewar (acting)
Essequibo— A. W. Sears
NorthWest District— L. E. McKinnon
Agricultural Assistants:

Demerara, East — J. Indrobeharry
Berbice— H. B. France

Sugar

Field Manager (Central Station)

C. Cameron
Field Assistants x
L. A. Forte
B. A. McArthur

METEOROLOGICAL BRANCH

Technical Assistant :

D. D, Blackman

Meteorological Assistant'.

J. E. Isaacs

RICE GRADING BRANCH

Grading Inspector :

H, E. H. Gadd (on leave)

H. D. Huggins (acting)

Technical Assistants :

G. L, Leitoh
R. R. Ross

ADVISORY BOARD OP AGRICULTURE

Director of Agriculture, Chairman, ex officio .

Deputy Director of Agriculture, Vice-Chairman, ex officio.

Hon. Peer Bacchus

Hon. R- E. Brassington

Hon. J. W. Jackson

...

► Members

Hon. F. J. Seaf ord, o.n.F

Mr. S. Andries
„ R. B. Hunter

...

„ W. H. Richards

...

SUGAR EXPERIMENT STATIONS COMMITTEE.

Director of Agriculture, Chairman, ex-officio.

Hon. M. B G. Austin, o.n.r..

Mr. H. F. Chapman (acting for Mr G. M. Ecclos) .
„ J. C. Gibson
„ A. Murison
„ R. E. Rhodes

„ J. Sutherland (acting for Mr. J. Bee)

Georgetown
Pin. Bath
Pin, Port Mourant
Pin. Uitvlugt
Pin. Diamond
Pln. f ()gle

CO-OPERATIVE CREDIT BANKS’ BOARD.

Director of Agriculture, Chairman, ex-offieio.
Dr. the Hon. J. B. Singh
Rev. A. E. Dyett ...

Mr. C. Farnum ...

„ J. L. Wills ..

Members

Representing
the Sugar
Industry
which main-
tains the
Stations

DISTRICT AGRICULTURAL COMMITTEES

EAST DEMERARA

Director of Agriculture, Chairman
District Commissioner
Doputy Director of Agriculture
Hon. J. I. de Aguiar
Hon. E. M. Walcott
Mr. S. Andries ...

„ M. Ghani
„ W. H. Richards
„ J.E. Wills ...

Members

Director of Agriculture, Chairman
District Commissioner
Deputy Director of Agriculture
Hon. J. W Jackson
Dr. the Hon. J. B. Singh ...

Mr. R. P. Carryl ...

„ J. C. DaSilva
„ R. B. Hunter * ...

A. Murison ...

,, W. Ramdeholl

,, A. Rayman ... ...

WEST DEMERARA

Members

CONTENTS.

(Vol. IX, No. 2.)

PAGri

EDITORIAL — The Rice Situation ..

ORIGINAL ARTICLES.

Malaria in British Guiana,
Parti.

... G. Giglioli. M.D. (1/.), M li.C.P.
D.T.M. & II. {Eng.) ...

(Land.),

Results of Padi Varietal Trials
and Extension Work, 1937

... F. Burnett, <I.C., M A. ...

The Variety and Fertiliser
Position of the Sugar
Industry, IV.

... Holman B. Williams. M.A.,

A.I.C.T.A.. Dip. Agr.

101

SELECTED ARTICLE.

Edible Coconut Oil

... Reginald Child, F.I.C., B.Sc.,
Ph.D. ( Lund .).

109

NOTES.

Boron in Agriculture

*'< ... |,|

117

New Ornamental Plants
in the Botanic Gardens

119

Legislation ...

... , 120

British West IndieB Fruit and
Vegetable Councils

* • * «»l n,

120

NEWS

••• ••• • ft «

120

PLANT AND SEED IMPORTATION

129

METEOROLOGICAL DATA

••• itt

130

CURRENT PRICES OF COLONIAL PRODUCE

131

Contents — Continued.

ILLUSTRATIONS

Pacing Page

Plate

I.— Fig.

1 — Anopheles alhitarsis: Adult Female,

,,-Fig.

2— Wing markings of (a) A. alhitarsis;

(b ) A. darling i.

... 76

Plate

II.-— Fig.

3— Caudal portion of the larva of A , darlingi.

,,-Fig.

4 — Papa? of (a) .4. alhitarsis; (b & c)

A. darlingi.

Plate

III.— Fig.

5— Breathing Trumpets of A, alhitarsis.

„ —Fig.

6— Breathing Trumpets of .4 . darlingi.

Plate

IV.— Fig.

1— Relative Varietal Composition of the Cane
Areas to be harvested in British Guiana
in 1938. ...

... 102

Plate

V.-Fig.

2— Relative Quantities and Values of Fertil-
isers used on British Guiana Sugar
Estates, in 1937.

107

Guiana.

The

Agricultural Journal of British

June, 1938.

EDITORIAL

THE RICE SITUATION.

Rice is the second most important agricultural industry of this Country,
The frequent standard of estimating the importance of the crop in relation to
the other industries is the value of exports. This may lead to an underestima-
tion of tho worth of this crop since rice is the most important article in local
diet ; consumption is increasing, the figure at present being approximately
24,000 tons annually, compared with an average export of 111,000 tons during
the last five years. These figures furnish a better means of appreciating the
crop’s real importance.

As rice is grown almost entirely by the small producer, the vicissitudes of
its production and marketing affect a considerable part of the Colony’s farming
population.

In agriculture, as in other walks of life, a proverb often quoted is : “ Man
proposes, God disposes/’ Man has made many proposals for the betterment
of the rice industry in recent years, but the latter half of the pro\erb has been
too much for him. For a number of years, up to 1933, rice production expanded
remarkably but early in 1934 there came a flood whose damage was only loss
than the ill-effects of the drought which followed and lasted for the rest <rt the
year ; the Colony’s rice exports were halved.

In 1935-36, production was again low on account of unfavourable weather
conditions. Further, rice prices declined steadily: for example, the average
price per 1 80 lb. bag of 44 super” grade was $4.02 in 1934, $3.83 in 1935 and
$3.39 in 1936. 1 Rice is a relatively short-term crop (compared, for instance, with
sugar) and the area under cultivation from crop to crop reacts sensitively to price
changes. Hence, although prices rose in 1937 — super rose to $3.85 per bag —
production, while taking an upward turn, was still below the high level
reached a f$w years previously.

74 AGRICULTURAL JOURNAL OP BRITISH GUIANA. [IX, 2,

The Fear 1938 broke with prospects for the rice producer distinctly
promising i a fair crop had been harvested and prices for forward shipments
were higher than they had been since 1934. Unfortunately, the first half of
1938 has been characterized by rains more continuous and more abnormal than
those of any year for which records are kept — the year 1893 alono excepted.
The effect has been to render milling difficult and in some instances to bring it
to a standstill. Almost all cf the rice produced in British Guiana is parboiled.
Padi is soaked in water, steamed and then dried on concrete floors in the sun.
If the interval between steaming and drying is unduly long, rice of poor quality
results. It is at this stage — the drying stage — that milling operations have
broken down within recent mouths, since intermittent showers have made it
well-nigh impossible to obtain sufficient sun to dry padi thoroughly enough for
milling. The significant result of this season’s experiences has been the fixing
of attention on the great necessity for improved drying facilities in the Colony’s
rice factory organisation. It is universally admitted that had factory equipment
included mechanical driers not only would good quality rice have been available
but the Caribbean markets would have absorbed a much larger part of our crop
at an attractive price before Burmese shipments began to arrive in April-May.
A feature of recent years has been the improvement in quality of padi through
the more general use by farmers of pure line seed distributed by the Department
of Agriculture ; it is unfortunate that the advantages of this improvement aro
not fully enjojed by growers on account of poor milling facilities. Out
of evil m^y ' yet come good, it this season’s misfortunes have
succeeded in demonstrating the necessity for improved rice factory
equipment in general and in drying facilities in particular.

In regard to the Market outlook it is not easy to make a forecast for the
latter part of 1938. The area sown in Burma in 1937-38 was the largest since
1933-34. Tndia is the leading importing country but production this season is,
with one exception, the largest since 1931-3*2. On the whole, therefore, imports
into India from Burma are likely to be relatively small. It is not possible to
gauge accurately what will be the imports into China since tho far eastern hos-
tilities must assuredly have far-reaching effects on the rice growing and consum-
ing areas. Production in the Japanese Empire has this year attained a record
and is in excess of the population’s requirements ; in addition, stocks at the
beginning of the season were large. Imports are therefore not likely to be drawn
upon. In British Malaya, relatively low rainfall led to expectations of a short
crop but the setback in the rubber situation is considered likely to affect rice
imports. The situation in Ceylon indicates that no great change is likely to take
place in regard to imports. Production in Java has been rising in recent years
so that not only have domestic supplies been met but exports have actually been
made to the Outer Provinces. These circumstances indicate that Burmese ship-
pers are likely to take steps to dispose of as much of their present crop in the
Caribbean as that market can be induced to absorb,

ORIGINAL ARTICLES.

MALARIA IN BRITISH GUIANA,

PART I. THE ANOPIIELINE MOSQUITOES OF THE COLONY,

G. GIGLIOLI, m.d. (It,), m.r.c.p., (Loud.); d.t m. & h. (Eng.).
Medical Adviser to the Sugar Estates of British Guiana.

The malaria problem, in all its phases, is intimately related to agriculture :
malaria is eminently a rural disease and rural and agricultural populations suffer
most from its ravages

Malaria is closely connected with the distribution of surface waters and
land configuration ; agriculture, by altering surface water conditions and land
configuration, through drainage and irrigation, directly affects, beneficially
or adversely, the incidence of malaria. Extensive agriculture often favours
malaria ; intensive agriculture, on the contrary, radically eliminates it. It
is by the forcible establishment of intensive agriculture in localities recently
reclaimed by drainage, where malaria had reigned supreme for ages, that such
brilliant results have been reaped, in less than a decade, in the Pontine marshes
and other classical malaria regions of central and southern Italy.

Agriculture, in this Colony, is eminently extensive in its type ; sugar and
rice : both these forms of cultivation are dependent on adequate irrigation ; sea
water is injurious and must be excluded, hence sea defences and elaborate systems
of sluices and pumping stations; rain and flood waters are stored in conservancies
situated aback of the cultivation, to feed thousands of miles of irrigation canals
which riddle the coastlands. Thus ideally favourable breeding sites are provided
for mosquitoes, at all seasons, and breeding continues the year around with
greater or lesser intensity, according to. the temperature and the individual
characteristics of each species.

In this Colony, perhaps more than elsewhere, the connection betweon agri-
culture and malaria is intimate : there can be no doubt that the prevailing forms
of cultivation, rice and sugar caue, influence the malaria problem adversely.

. Malaria is a mosquito borne disease ; not all mosquitoes are capable of trans-
mitting it; this pernicious role is exclusively restricted to mosquitoes of the genus
Anoplwles. These facts can now be regarded very nearly as common knowledge;
but it is not, as yet, at all appreciated that the carrier problem must be restricted
to yet a much mere limited field : only a relatively small number of species, in
fact, out of the many included in the genus Anopheles have practical imimtanee
in the transmission of malar ia.

76 AGRICULTURAL JOURNAL OP BRITISH GUIANA. [IX, 2.

Some speoies of Anopheles are not sasoeptible to infection, even when
repeatedly fed on patients harbouring abandant malaria parasites in their
blood, in the phase suitable for mosquito infection. In others, infection occurs,
bat the parasite appears unable to undergo its full development and fails to reach
the stage in which' it again becomes infections to man when inoculated in the
blood stream through the mosquito’s bite. Such species of Anopheles, evidently,
are constitutionally unfit for the transmission of malaria and their practical im-
portance to the malariologist is nil.

There are other species of Anopheles which in the laboratory can be
infected with malaria with the greatest ease, but under natural conditions very
rarely become infected as they bite animals selectively and man only as the
exception. It is very unlikely that an individual mosquito, belonging to one of
these “ zoophylous species ”, should bite man repeatedly at the interval
required for it to become infective. Transmission of malaria by such species
is evidently possible, but sufficiently unusual to lose much, if not all , practical
importance.

With gome species zoophyliu is a constant characteristic ; in others it may
be acquired under favourable conditions ; thus a same species of Anopheles
may be found to be a dangerous carrier in one region, whilst it is zoophylous, and
therefore harmless, in others. Such is the case with the species Anopheles
muculipennis, the main vector of malaria in Europe ; with the advent of inten-
sive agriculture', which implies an abundance of livestock and animal shelters,
this species tends to restrict its biting activities to the shelter of stables, cowsheds
and pig-sties ; “ biological varieties ” evolve which do not attack man, and thus
lose all importance as natural vectors of malaria.

In England, in the districts where malaria, in a not too distant past, used to
be endemio, A . maculipennis still abounds, not in homes but in animal shelters.
We have seen it in enormous numbers in Surrey pig-sties and cow barns. Like-
wise in Italy zoophylous biological varieties of this species exist at present in
localities which were malarious only a few decades ago.

In the American tropics, some .‘10 or 40 species of Anopheles have been listed
by various authorities. These species vary widely in their geographical distribu-
tion, their feeding and breeding habits and in their infectability to malaria.

We have outlined these facts as they constitute the basal principles on which
rational malariology is founded.

In any given malarial locality the following are the first and basal problems
to be resolved :

(U The identification of the local existing Bpecies of Anopheles.

(2) The distribution and incidence of such species in relation to the dis-
tribution and incidence of malaria,

MALARIA m BRlflS tt GtJIANA. 11

(3) The detailed biology of each species with special regard to breeding,
biting and flying habits*

Once these data are folly acquired we have at oar disposal the means for
intelligent, direct and, above all, economical malaria prevention : onr whole effort
can be concentrated on the control of the species which is or are the proven vectors
oj malaria in the region ; the others may be ignored in all safety.

The conditions we have found in this Colony are a very striking example of
this definite limitation of the malaria problem to a single Anopheline specks.
The practical importance of this fact is too obvious to be stressed : it means that
for the control of malaria in British Guiana we must deal with a single species ,
subject to certain definite limitations in its breeding habits ; we can, on the
other hand, ignore other species of Anopheles, much less exacting, as we shall
see, in their breeding requirements. In consequence of their greater adaptability
these latter species are very much more widely distributed and abundant so
that, given the physical configuration and climate of the colony, their control
would be practically impossible.

The whole classification of tropical American Anophelines is, at present,
under revision as methods have been perfected greatly of late years ; the
anatomical characters of the males have acquired great taxonomic importance.

It is by no means possible, at present, to give a complete catalogue of the
local species of Anophelines ; we can only mention those which we have
encountered in onr personal experience of some 15 years, From lfi34 to the
time of writing we have examined and identified over 20,000 specimens collected
from numerous coastal localities between the Essequebo and Corentyne estuaries
and from the interior, on the Demerara, Essequebo and Potaro rivers. We are
indebted to Mr. and Mrs. H. E. Turner for a collection of 70 Anopheles captured
in various localities on the Bupununi Savannahs in August 1030.

Three species of Anopheles are widely distributed and very abundant in
the Colony. They all belong to the sub-genus Xyssot hynnis the members of
which can easily bo recognized by the silvery white extremities of their hind
legs. We will not go into detailed descriptions, limiting, our exposition strictly
to the main differential characters which are of practical importance in the field
and in the laboratory for routine identification purposes. The more important
of these characters are very plainly visible in our series of micro-photographs.

A . tarsi maculatus . This species can easily be identified with the help ot a
simple magnifying glass, as it possesses a black spot or ring at the base of the
last segment of the hind logs. It is ubiquitous : we have specimens captured in
houses in Georgetown, from West and East Demerara, from Western Berbice
and the Corentyne coast, where we have found it particularly abundant. It
is occasionally found along the rivers in the interior, wherever some clearing
of the forest has been effected. This species is also represented in our collec-
tion from tlje Hupununi.

AGRICULTURAL JOURNAL OF feRItlSH GUIANA.

[IX 2.

We have also observed the occurrence of a known variety of A . tarsima-
culatus characterized by having a larger portion of the hind legs white ; (the
black portion of the 2nd tarsal segment is represented by only a narrow ring
at its base). We have specimens of this variety from the Berbice Estuary and
from the Rupununi Savannahs.

The existence of A. tarsi maculat us in the Colony has long been known.
Bodkin and Cleare observed that it abounded in localities which were only
mildly malarial. It has been regarded as the principal carrier of the disease on
the coast. Flu and more recently Bonne and Bonne Wepster expressed the
same opinion as regards the coastland of Surinam,

In our own experience, though the larva* of this species are by far the
most commonly and easily found, ^4. tarsi, mandat us is relatively rarely caught
in the dimly lighted native houses : but it is not at all uncommon to capture it
in bright, electrically lighted estate hospitals or staff houses. It 'is evidently
attracted there by the light as myriads of other winged insects. A . tarsnua-
rnlatus becomes active at dusk ; but occasionally and in proximity of its breed-
ing sites, it may attack in large numbers and in full sunlight when disturbed from
its resting places in high grash or bushes. It can be found at all seasons,
throughout the year, but is much more abundant during the warmer months
from May to October.

A. tarsi mat ulatus abounds in stables, cattle and sheep pens, and can easily
be caught on horses and cattle in the open, after sunset. With Mr. Komp, of
the United Stages Public Health Son ice, in July 1030, we observed this species
in countless thousands in cattle sheds at Gibraltar, on the Corentyne coast, some
10 miles east of New Amsterdam. This locality is practically free from
malaria. The sheds were open to the strong sea breeze and the Anopheles were
crowded over the timber sills forming tbe base of the building, some 6 inches off
the ground ; many were actually resting on the rough, damp clay floor evidently
resisting the strong breeze with considerable difficulty. Males were also
piesent in large numbers, this fact indicating the close proximity of their
breeding sites in the extensive Iron Hand brackish marshes. A. iarsunucututus
haunts savanna] countries open to sun and wind : it is a hardy species and its
resistance to the desiccating action of the wind is very considerable.

This species shows remarkable adaptability and latitude ill the choice of its
breeding sites ; irrigation canals, drainage trenches, flood fallowing cane fields,
rice fields, flooded pastures and savannahs, swamps, marshes, ponds, rain water
collections of all kinds, puddles, cow holes, ruts, clean water and dirty water,
salt, brackish and rain water, strongly acid, neutral and alkaline water, all
suit it and in all it flourishes. Brackish waters are probably its favourite
breeding sites, lienee its abundance in the extensive salt marshes of the
Corentyne coast froutlands. The pH of waters in which *4. farsiutarulatus was
found breeding ranged from 4 to 7.8 ; the sodium chloride concents from
g. 0.005 to g, 2S.000 per litre*

Fig, 4.— Pupae of : %

(a) A . albitarsis (note scoop-shaped breathing trumpets).

• (b & c) A. tlarlinyi (the margins of the breathing trumpets are deeply indented).

MALARIA I ft BRITISH OtTIANA.

7£)

The two following species, A. dibit arsis ahd A . darling ! , though extremely
common, have not previously been identified in this Colony, being in the past
regarded as a single kind under the erroneous designation of A. argyritarxi * .
This confusion is easily explained by the close similarity among the adults of
the Nyssorhyncus group ; on the other hand, the differentia) characters which
are revealed by closer examination are so evident and distinctive that it is
surprising they should have eluded detection for so long.

A . argyritarsis is a valid species first described in Panama ; its importance
as a malarial vector was there regarded as of small moment. It occurs in
Brazil, but, up to recently, even in that country, it was currently and widely
confused with the following two species.

Exact information on its geographical distribution is still lacking : so far
we have failed to find it in this Colony. This, evidently, does not exclude
definitely its presence, but we feel authorized to state that even if it does occur
in small numbers; or in restricted foci, the importance of this species, in relation
to the malarial problem in British Guiana, is nil.

A. albilarsis : the adult insects of both sexes can be easily recognized by
the presence of two parallel rows of conspicuous white scales on the ventral
surface of the 1st abdominal segment (l.s/ slrrmtr). In dried specimens,
through retraction, the sternite is usually concave so that these lines of scales
acquire a V — like or converging disposition. Fig. I shows the latero- ventral
aspect of a female -1. nlb*(an>*s , one of the rows of scales we have described is
clearly visible.

Fig. II demonstrates the differences in the wing markings of -l. albUamx
and .1. darling* : the different disposition of white and black markings of the
the costa, or anterior wing rib, at its base, should be noted : in the former (a)
two small black spots stand out in contrast on the white background ; in the
latter (b) the colour scheme is reversed and two small light coloured spots
stand out on a black background. The light coloured wing scales of A. alfntars*s
are white ; those of *1. darling! are golden yellow.

The larva* of A. fanunandatns and A. affntaisis though very similar, can
be differentiated in the laboratory on the characters of some of their ornamental
hairs, but for this purpose a certain amount of experience is necessary. The
pupm of these species vary considerably in colour, from dark to light brown,
yellowish or bright green ; we know of no good character for their differentiation.

The distribution of A. alhilarvis in the Colony is wide ; we have collected
It in West and East Demerara, in Western Bcrbiee and on the Corcntyno coast ;
we have never observed it in the forest areas of the interior and* we doubt its
existence in such districts. Ninety per cent, oi our specimens from the ltupu-
nuni belong to this species.

A . albikims presents a well marked seasonal incidence : it appears early in
May and continues throughout the warmer weather to October or ifovember,

80 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 2.

fluctuations occurring from year to year according to variations in the seasonal
distribution of the rainfall. It is very unusual to find this species between
December and April.

The favourite haunts of A . alhi tarsi s are open savannahs and pastures
where cattle abound. It occurs in great numbers on the back dams of Western
Berbice estates and on the Abary savannahs. It naturally flies and feeds after
dusk, but if disturbed from its shelter in the grass or bushes it will attack
viciously and in full sunlight. Hiding on the Abary savannahs and, we under-
stand, in the Rupununi, is often made very unpleasant by the attentions of this
mosquito. It is little affected by high breezes and, on the whole, we have found
it a much hardier species than the following one.

In the selection of its breeding sites it appears to favour large bodies of
water well exposed to the sun ; flooded savannahs and pastures ; flood fallowing
canefields ; ricefields ; irrigation canals, etc. It also occurs occasionally in ponds,
small drains and temporary rain water collections.

The waters in which it breeds are clean, slightly acid or neutral in reaction,
with a low content in soluble salts (pH range G.G to (5.9 ; sodium chloride 18 to
30 milligr. per litr^).

*1. durhnyt : the adult insects of both sexes in ttys species present the fol-
lowing differential characters : the distal half of the 2nd and all of the 3rd,
4th and 3th tarsal segments oi the hind legs are snow white ; the wing mark-
ings are distinctive, and there are no white scales on the 1st abdominal sternite.
These characters have already be«»n described when dealing with *4. albit«rsi«
aud are well illustrated in Figs. I and II.

The larva of .4. darlnigi presents a very striking and unique character in
the form of two long, straight bristles, surmounting papilla' placed on the dorsal
plate of the spiracular or breathing mechanism. These bridles are directed
dorsally so that when the larva lies horizontally just below the water surface,
they protrude through the surlace film ; they are very clearly shown in Fig. Ill
and can be detected already in the v 2nd and 3rd stage of larval development.

The pupa of A. durVnnji is equally well characterized ; its colour is always
dark brown ; the breathing trumpets which in -1. iarxiiHaaifahtx ami A. albdttr -
nix are delicately ctntinizcd with a plain scoop-like shape, in A. darlinyi have a
very much more elaborate structure : the trumpets are heavily chitinized, more
open and present on their lateral margins deep indentations which give rise to
two very characteristic finger-like projections. Our micro-photographs illustrate
these characters more effectively than any description (Figs. IV, V, and VI ).

.1. (Uirliwji was first described by Root at Bahia, Brazil, in HhJG: the
investigations of Shannon, Davis, Kumm, Benniroch and others have demon-
strated its wide distribution in equatorial South America. It ranges from the
foot hills of the Andes throughout the Amazon valley to the Atlantic seaboard ;
it occurs in Venezuela and we have established its presence in British Guiana ;
itA southern range is not, as yet, fully determined.

PLATE in.

Flu. (5 Breathing trumpets of A. datiirvji.

Malaria in British guiana.

In the Colony it is the Anopheles of the forest areas of the interior on the
tidal and flood rivers ; we have collected it in large numbers on the mid and
upper Demerara, on the Essequebo and Potaro Rivers. On the coast it is often
associated with A . tarsi maoulatus and A . albitarsis but its general distribution
does not follow these two species. In some coastal localities it is extremely
abundant, particularly on the estuaries of the Demerara and Berbice rivers and
on the West and East Coast of Demerara. So far we have had difficulty in find-
ing it at Cane Grove and it is definitely rare along the sea coast of Western
Berbice. It represented only 8.3% on 097 Anopheles captured in houses on Bath
Estate between 1934 and 1937. This species occurs also in our Rupunnni collec-
tion : a single specimen was captured on human bait in a partly forested district
at the foot of the Kanuku Mountains.

The three species we have described, A . tarsi mnculatu>% *4. albitarsM, and
A. darling i , between them, account for 99.9% of the 20,000 adult Anopheles we
have collected and identified. All the larvae and pupae we have examined,
without exception, belong to these three species.

Other Anophelines, evidently, occur in the colony but always in small
numbers and it is quite exceptional to capture them in houses. We have some
female specimens of two different species belonging to the Arribaha gut group ;
they were all caught in wooded localities, on the the mid-Demerara, on the
Berbice Estuary and in the Rupununi District, most of them on animal bait in
the open ; larvae and males have not, as yet, been found and for this reason
their exact identification is still doubtful.

A. (Stelhwmjidj nimbus has been reported from the Colony and Komp
found it common in the forest at Kartabo in July 1936.

It is quite evident that these and eventually other rare, or at least
Uncommon, species, can havo no practical importance from a maiariological stand-
point. Malaria in British Guiana is extremely prevalent and widely distributed}
its carrier or carriers must therefore, evidently, be equally common.

We have seen that A. tarsi maculat us, .4. albitarsis and A. ddrhngi are
all extremely numerous with a wide range of distribution, all of them, therefore
in this respect could adequately fill the role of malaria carriers.

The relative importance of each one of these species in regard to thd
transmission of malaria, under local conditions, will next be treated.

^ To h Conti nut tf )

RESULTS OF PADI VARIETAL TRIALS AND EXTENSION

WORK, 1937.

P. BURNETT, M.C., M.A.,

Deputy Director oj Agriculture.

During the Autumn Crop of 1937, fourteen variety trials wore laid down,
six standard trials containing the same varieties for trial at various centres in the
Colony, and eight trials with promising varieties. The sites of these experiments
were as follows: —

Berbice : Whim.

No. 63.

Demerara : Georgetown Rice
Station.

Hope, East Bank.

Vreed-en-Hoop,

Essequibo : Henrietta.

Leguan.

Wakenaam.

The results are presented in Tables I and 11.

Under the supervision of Mr. J. D.
Gillespie, Agricultural Superintendent.

Under the supervision of Mr. E. M.
Peterkin, Agricultural Superiutendent.

Under the supervision of Mr. H. D.
Huggins, Agricultural Superintendent.

Under the supervision of Mr. A. A.
Abraham, Agricultural Superintendent.

Under the supervision of Mr. E. G.
Benson, Agricultural Superintendent.

Standard Trials,

RESULTS of paDi varietal TRlAlia.

Table II.

Padi Trials — X e\v Varieties.

RESULTS OF PADI VARIETAL TRIALS.

The following conclusions may be drawn from Table I. : —

(a) Vreed-en-Hoop. D99 is significantly superior to all other varieties
except D114 , which surpasses the rest except Demerara Creole,
D109 and DUO.

(b) Leguan. There is no significant difference between DllO, Kahja-
man, No. 79 and DU4, but the first three are significantly superior
to the other four varieties tested.

tc) Wakenaam. Again the first four varieties D114, D99, DllO, and
No. 79 are equal to one another. The other varieties tested are all
inferior to these with the exception of Kahjaman, which is surpassed
only by Dll 4.

(d) Whim. There is again equality among the first four varieties
Kalyaman, Demerara Creole, DllO and Dll 4 of which Kalyaman
alone surpasses the rest. D99 is significantly inferior to all the
others.

(e) No. 03, Berhiee. Equality again exists between the first four
varieties Dl 14, D99, Kahjaman, and DllO, of which DU4 alone
surpasses the rest. D109 is surpassed also by D99 and Kah/aman.

The following conclusions may be drawn from Table II. : —

(a) floor get men ( Experiment No. l). D114 was superior to all the other
varieties tested except D221, D97 (B) and Demerara Creole,

(b) Georgetown ( Experiment No. 2). D99 far outyielded the other

varieties tested. Demerara Creole and No. 79 were disappointing.

(c) Georgetown ( Experiment No. 4). D114 was outstandingly superior.
Bl and Demerara Creole were bracketed second, while the other
four varieties were significantly inferior.

(d) Georgetown (Exjteriment No. .5). Dll-5 was superior to all the other
varieties, No. 79 again disappointed.

(e) Knot Bank, Demerara. D114, Demerara Creole and D109 were
bracketed first, of which 1)114 was significantly superior to the rest.

(f) Henrietta (Experiment No. /). Dl 14 was superior to the other
varieties tested except D99, which in turn surpassed the rest except

Dl09.

(g) Henrietta (Exi>eriment No. 2). D114 was again superior to the
other varieties tested except DllO, which in turn surpassed the rest
pxcept D109,

36 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 2,

SUMMARY OF ALU TRIALS,

A general comparison between all the varieties tested during 1937 is shown
in Table III, which is shown graphically. The average yields per acre of the
varieties are calculated as percentages of the Demerara Creole yield which is
taken as the standard,

Table III.

Summary of 1937 Variety Trials.

Variety

No. of

Trials.

Average Yield per acre
Compared with Demerara Creole.
(100.0)

D114

117.1

DUO

110.2

D99

106.1

D91

1 103.7

D109

1 103.6

Kalyaman

103.0

Dll 6

, 102.1

Blue Stick

. 99.0

No. 79

97.3

1 i

96.5

D88

92.6

D97 (B)

2 !

90.2

D221

90.0

D89

89.1

D90

88.9

DUS

2 1

88.(5

D92

87.2

D228

85.4

83.0

81.9

Blue Stick Strain Trial.

Four strains of the Blue Slick variety were selected and tried out in a trial
in 1936. This experiment was repeated in 1937, and the results are shown in
Table IV. . As in 1936, no significant difference was revealed between the yields
of the various strains, and it is concluded that the Bine Stick grown on the
Henrietta Station is pure, so that no further advantage can be gained by selection
within the variety.

RESULTS OF FADJ TARIETAL TRIALS.

Table IV.

Site

Henrietta

Layout

5X5 Latin Square

Strain

Padi per acre, lb.

Ordinary Blue Stick

2808

Strain 4

2760

Strain 2

2692

Strain 1

2612

Strain 3

2552

Significant Difference P = .05

Long Grain Trial.

Four long-grained rices were received at the Henrietta Station in 1037, and
they were put in a trial to see how they compared with the ordinary Blue Stir h
cultivated on the Essequibo Coast. The results of the trial Bhown in Table V
reveal no signitioant difference between any of the varieties.

Table V.

Site

j Henrietta

Layout

5 X 5 Latin Square

Ordinary Blue Stid< 1

4020

Seymour Padi 1

3768

Jaisingh Padi

3760

Ramjess Padi

Sue’s Padi,

3560

3520

Significant Difference P = .05

88 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 2,

Varietal Notes,

The following is a summary of the past performances of some of the more
important varieties : —

Demerara Creole. In 1930 this variety came third in the Essequibo and
Berbice trials, fifth in the Demerara trial. In 1931 it came third in the
Demerara, fifth in the Essequibo trial. In 1932 was fifth in the Demerara, third
in the Essequibo trial. In 1933 was fourth and fifth in the Demerara trials,
fourth in Essequibo, In 1934 it was fifth in two Demerara trials, seventh in
Essequibo. In 1935 it was extensively tried in ten trials, and could surpass
No. 79 only four times. In 1936, in twelve trials, it was beaten by No, 79 ten
times, and in eight trials with Blue Stiel was beaten six times. 1937 selections
improved on the 1936 performance and outyielded No. 79 in nine trials out of
fourteen.

No. 79. In 1930 this variety outyielded ail varieties in two trials, and came
second in another. First place was again taken in two trials in 1931. In 1932 this
performance was repeated, and in 1933 again it proved superior iq three trials.
In 1934 it came second in two trials, but made eighth place in another. In 1935
it gained two firsts and three seconds in ton trials, followed this up in 1936 by
surpassing Demerara Creole ten times in twelve trials. In 1937 it unaccount-
ably failed, and its performance was very poor, being surpassed by Demerara
Creole nine times in fourteen trials.

Blue Stick. This variety did well in one trial in 1930. Tried twice in
1931 it was second in Essequibo but sixth in Demerara. Tried only once in
1932, it came second in Essequibo. It jumped up to a consistent second place
in each of three trials in 1933, and repeated this good performance in 1934
by coming first in Demerara and second in Essequibo. In 1935 its yields
were only average, but it did extremely well in 1936, when it surpassed
Demerara Creole six times out. of eight, and No. 79 six times out of ten. In
1937 it was tried only twice, at Essequibo, and came sixth each time.

V. 114. This variety made its debut in 1934, and came second in its one
trial. In 1935, placed in six trials, it outyielded Demerara Creole every time.
Blue Stick four times and held its own with No. 79. It put up a wonderful
performance in 1936, gaining four first places, three seconds, and two thirds in
thirteen trials, and in 1937 this was even bettered when it came first in eight
trials out of eleven, being beaten by Demerara Creole and No. 79 only once.

D. 110. This variety first appeared in a trial in 1935, when it was fourth,
yielding higher than Demerara Creole , No. 79 and Blue Stick. In 1936 it was
placed in eight trials and surpassed Demerara Creole every time and No. 79 four
times* In 1937, appearing in nine trials, it snrpassed No. 79 eight times, and
Demerara Creole three times.

RB8ULT8 OP PADI VARIETAL TRIALS.

D. 99. Like D. 110, this variety oame oat in 1935. In three trials it came
first twice. Appearing in only two trials in 1930, it was first in both. This
splendid performance was continued in 1937, when in ten trials, it gained two
firsts and five seconds, surpassing Demerara Creole and No. 79 seven times each ;
only the outstanding D. 114 could give better yields than this variety during
this year.

Miscellaneous Trials.

A trial was carried out at Henrietta in which transplanting seedlings of
different ages was tested oat. The results of this trial are shown in Table VI.

Table VI.

Site

Henrietta

Layout

5X5 Latin Square

Age of Seedlings

Padi per acre lb.

3 weeks old

4072

4 ,, ,,

4008

5 ..

3904

Double Transplanting

3800

6 weeks old

3704

Significant Difference P = .05

188

_ _

„

The following conclusions may be drawn : —

(a) There is no significant difference bet weed’ seedlings transplanted
3, 4, or 5 weeks old,

(b) Double transplanting and transplanting seedlings 6 weeks old are
both inferior to seedlings transplanted 3 weeks and 4 weeks old.

(c) Transplanting seedlings 5 weeks old is not superior to double
transplanting, but is superior to transplanting seedlings 6 weeks
old.

The results of this experiment agree with those obtained in 1935, both
showing no significant differences between transplanting seedlings 3, 1, or 5
weeks old, with, however, a trend in favour of the younger seedlings.* The
results of 1936 are in conflict with these two results. A further trial may give
some definite answer to this problem,

90 AGRICULTURAL JOURNAL OR BRITISH GUIANA. [IX, 8,

Table Y1I presents the resalts obtained with planting different numbers of
seedlings per hole.

Tablb VII.

Site

Henrietta

Layout

5x5 Latin Square

Number of Seedlings per hole

Padi per acre lb.

28(H)

206

2460

2436

2388

Significant Difference P = .05

11)4

There is no significant difference between the yields obtained from 7 and
5 seedlings per hole. Both, however, give significantly higher yields than 3,
2 or 1 seedlings per hole. These results are in direct contrast with those of 11*36,
in which experiment fewer seedlings per hole were significantly superior to
greater seedlings per hole. Farther investigations must be carried out to obtain
definite information.

Purity oi Padi Cultivations.

Daring the 1937 Autumn Crop the usual estimations of purity of padi
cultivations were carried out in the various districts. These estimations are
shown in tabular form in Table VI 11. In each district can be seen at a glance
the total acreage under rice cultivation, and the areas of pure line and purities
of approximately 90%, 90% — 75%, 75% — 50%, and under 50%. These areas are
calculated in percentages of the total acreage, and from these figures are derived
the percentage area of a district which shows purities greater than 75% and 50%
respectively.

Information regarding the area of seed farms supplying each district is also
given*

RESULTS OF PADI VARIETAL TRIALS,

92 AGRICULTURAL JOURNAL OR BRITISH GUIANA. [IX, 2.

Progeny Rows,

1. Georgetown Experiment station.

At the end of the 1937 Autumn Crop gome of the varieties were not
considered worthy of being kept any longer in the progeny rows. These pedis
were under observation for several seasons, and their characters proved to be of
little value. The following is a list of the varieties which were discarded ; —

Dis< ari>kt) Varieties,

Variety,

Date

Received,

No record

No. 77

No. 7ft '

Sept. 1928

(Ian ka san navari

Kristna Kata Kului

Peru 1

4.12.29

Sago

30.9.31

Sonacalif j

,30 3.33

Louisiana I

18 7 33

ok shot ;

17.hl.33

Theik Pan

Jujjai

27.10.33 "

Prong 3G

Basmati

7U 33

Mushkati 7

„

Magoi

Kataktara

10.1*34

D 154

13 1 34

D 157

3.2.34

D 158

D173

19 £34

D 175

D 181

D 190

D 191

I) 195 1

164.34

Orealla 1

2H.8.34

Oerang-Oerangan
Paloe Alessoe

30.K.34

Maoemi

j * 1

I) m

D 235

1 1011.34

L‘237

19.11.34

B 2

1931

B 8

C 1

1 «

Origin.

Reaaons for 1 No of Seasons
Discarding. j Tested.

No record I Poor yield 7

M „ i „ „

. 7

Madras, India Poor yield, short grain 7

„ „ Poor yield, short grain 7

Peru Poor yield, awned grain 7

Her bice Small grain ft

Fiji Islands /Poor yield r 0

Louisiana „ „ ' j G

Mandalay 'Poor > ield, small grain] o

Poor yield, small grain] f>

Larkana, Sind Poor yield, \ery thin i 5

, K*rain

1 , » Poor yield, small grain 4

jPunjab, India Poor yield, very thin G

»«

grain

Poor yield, very thin
grain

Assam, India

Poor yield, small grain

Poor yield

Bombay

Poor yield, small grain

Tanganyika

Poor yield

‘Central Pro-
' vinces, India

iPoor yield

|Poor yield, small grain

United Pro-
vinces, India

Poor yield

Tanganyika

Pcor yield, thin grain

Poor yield, thin grain

,Poor yield

11 V

;Orealla, Oor-
entyne

,.Tava

Poor yield

Poor yield, awned grain

Sind, India

Poor j ield

'Poor yield, thin grain

» 11

Poor } ield. thin grain

jrsorth Borneo

Poor yield, small grain

Hybrid of D (\ x'Poor yield
| Americano 1000

Hybrid of Mexi
can Edith x D.O

i> i>

Comparison between yields of varieties tested and Dem

l P*o

f>4 AGRICULTURAL JOURNAL OP BRITISH GUIANA. [l£, 2.

The following list comprises the total number of varieties which are now
being tested ut the Georgetown Experiment Station. The table shows the
varieties* with places of origin and dates received, the number of seasons they
have been tried, their average yields per thousand plants over these seasons, and
their grain characteristics, whether long, medium, or short.

Varieties Under Test at Georgetown Experiment Station.

Vai iety.

Date
reeel \ oil.

Origin.

No. of
seasons
i tested

Yield
per 1,000
plants,
lb.

Type of Grain.

Demerara Creole

No record

No record ,

61.1

Long

Blue Stick

62.6

Medium

McKenzie Large
McKenzie Small

03.2

70.7

Short

H7.

„ i

61.2

Medium* long

No. 75

Probably i

54.7

No. 76

India

Local

56.9

Long

No. 79

selection

01 0

Medium

Rnmcajara

Sept.' 1 929

Madras,

61 4

Medium, broad

Ak Kulu

74.7 '

Short

Air,. 34

Oct. 1 1128

India

Burma

7 !

56.0

Medium-long

014. 31

67.1

Short, broad

Toledo

1 17.il/2S

British

25.0

Medium, broad.

District

Lead Rice

11.12.29

Honduras

Mr. Abdool

61.4

1 Short, broad.

No* 36

28.1.30

Ray man
, Trinidad

l 7

59.4

' Medium, broad.

No. 11 ;

! 6

74.5

Short, broad.

Kaly aman

1 7

, 54.0

Long.

Rupununi

1931

Rupununi

25 6 i

1 Medium, broad.

White Pin i

30.9.31

! Berbicc

22.4

44 4J

Minulabon j

11.4,32

' Philippine

! 6

62.5

Medium

DH8 i

12.10 33 1

j Islands
| Local selection.

63.7

, Medium, Long.

D89

„

' W.C. Demerara.

1 44

! 5

1 71.9

I Long.

1)9) j

1 14

, 5

1 77.9

1 44

D 91

1 H

, 5

63.6

1 44

I) 92

, 70.6

Medium-long,

D 94

1 ”

1 6

69.6

j Medium.

D 95

1 5

53.6 ‘

D 97 A

1.10.33

Local selection.

1 5

j 61.2

D97B

Expt. Station

t M

1 3

1 69.7

D99

1 7

1 „

1 4

70.9

D 100

n.ioiss

61.2

Medium-long.

Karimganj

Mandalay

< 5

84.8

Short

D 108

D 109

18.10.33

1 Local selection.
W,C. Demerara.

1 6

78.9

73.4

Medium

Medium-long

D 110

p •

' 5

68.5

Medium.

0114

68.0

Medium-long,

r> ii5

1 *

86.3

kagULtfS Ol* PADI VABIfiTAL TltlALS.

Variety

Date

received.

Origin.

No. of
seasons
tested.

Yield 1
per 1(KM) 1
plants, 1
lb.

P 116

18.10.33

Local selection,
W.C. Demerara

73 6

Unity

9.11.33

Unity, E.C. Dem.

88.3

D 136

10.1.34

Assam, India

Tanganyika

54.8

D 160

„

3.2.34

57.3

D 156

58.5

D 160

28.2.34

Bengal, India

59.2

D 162

69.4

D 176

19.3.34

Central Pro-
vinces, India

63.5

D 183

16.4.34

Madras, India

74 8

1) 184

510

D 186

Tanganyika

57.9

D 193

17.5.34

69 1

I) 205

North Borneo

53.0

Kao Bang Pra

17 7.34

Siam

37.7

J) 221

13.9.34

Local selection.
Berbiee

67 6

D 222

53.9

I> 224

t ,

67.2

P 225

57.2

D 228

2.10.34

North Borneo

63.7

P 236

19 11.34

47.8

D 23H

62 0

D 239

27.11.34

Local selection,
Essequibo

81.7

1) 242

3.11.34

Local selection,
W.C. Berbiee

56.1

P 243

Local selection,
Essequibo

59.8

D 244

27.11.34

78.2

D 245

Novr. 1934

Local selection,
i Berbiee

59.5

P 246

7.10.35

Local selection.
Expt. Station.

i Surinam

. 71 6

P 247

10.10.35

HI. 3

P 248

I 31.3

P 249

9.10,35

•j

13.4

P 26*)

| Local selection,
Wakenaain.

j 73.9

P 261

Local selection, ' 1
Leguan.

• 7') 5

I) 253

| 15,10,35

!•

1 1

P 254 !

i • «

85.6

D 255

25.10,35

Local selection,

I Vreed-en-Hoop.

i 110.2

P 256

i 92.9

D 257

i 11

1 " 1

•2

I 106.2 !

D 258

i *’

82.2

D 259

4.12.36

85,1

D260

Local selection,
W.C. Berbiee.

38.4

D 261

t 54,1 i

P 262 j

1 „

46.6

D 263

1 Local selection,
Skeldon.

37.2

D264

1 Local selection,

| Skeldon.

35,7

D 266

8 3.36

Sierra Leone

46.4 i

P 267 •

4.5 >

P 268

25.0

P297

Novr. 1937

Local selection,

...

,,,

Padi, B*ce.

1936

Expt. Station.

liOOftf 8$l6CtlOD|

Berbiee.

100,7

Type of
Crain.

Medium-long

Medium

Short

Medium -long
Medium

Short

Medium

Long

Medium-long

Medium

Long

Short, broad
Medium

Medium-long

Medium

Short

Medium

Medium.

Medium-long.

Medium

Medium-long

Medium -long.
Medium,

Lon^.

Medium,

Medium- long.
Short,

Long.

Medium-long,

AGRICULTURAL JotTRNAL OF BRITISH GUIANA.

[IX, 2.

Date

received.

No. of

Yield per

Variety.

Origin,

seasons

tested.

1000 plants,

Type of Grain.

Nickerie Patna

1935

Local selection,

75.4

Medium-long

Berbice

Seymour S.

1936

Mr, Seymour

76.8

Long

No. 1—37

1931

Hybrid— D.C. x

72,1

Short

Americano 1600

„ 3-37

607

Short

„ 4-37

64 5

Medium

„ 5- 37

62.3

„ 7-37

”

65.9

„ 8 — 37

72.7

„ 9— 37

72.1

Short

„ 11-37

Hybrid-Mexican
Edith x D.C.

6 1.6

Medium-long

„ 12-37

Hybrid-Kristna
Kata Kulu x No 79

71.1

Medium

„ 13—37

80.6

Long

„ 14-37

69.4

Medium

„ 15-37

»i

82.4

i, 16-37

75.9

„ 17-37

89.8

„ 18 -37

73.1

• 9

„ 1<> — 37

82 (5

.. 20-37

7(1,3

21-37

„

56.1

„ 22—37

„

64 8

„ 23—37

75 7

24-37

47 9

Medium long

„ 26 -37

52 5

Long

26—37

56.5

Medium-long

27-37

57.1 j

| Long

„ 28 - 37

1 ,

68.1

( Meilium-long

29-37

2 ,

72 1

, Medium-long

„ 30-37

65.1

Long

31—37

i „

I 2

• 67.5

1 Medium-long

„ 32-37

No\r. 1937

! Local .selection,

l • • »

Medium

Expt. Stn.
G f town.

33-37
„ 34—37
„ 35-37
„ 36- 37
„ 37-37
„ 3S— 37 1

! «

- !

i 1

1 ;;

• • |

# t9

Medium- long

„ 39-37
„ 40-37
„ 41-37

i, 1

ii i

1 1

• t

Long

» 41-37

42-37
„ 43-37

•••

i Medium-long
Long

44-37

„ 45-37
„ 46-37

„ i

i !!!

...

„ 47-37

„ 48-37

„ 49-37

Local selection,
Expt, Station,

i :::

Medium-long

Henrietta.

;

„ 50 -37 ->

,, 5t — 37

. • •

Long

„ 62-37

...

53-37

1- ”

...

kBSULTS OF PAD I VARIETAL TRIALS. t )*

Variety

Date

received.

Origin,

No, of
seasons
tested,

Yield
per 1000
plants,
lb.

Type of Grain.

No. 54—37

Nov. 1937

Local selection,
Expt, Station,
Henrietta,

...

Long,

„ 55-37

...

Medium-long.

„ f>6— 37

57 — 37

...

„ 58-37

„ 59-37

„ 60-37

! |

„ 61-37

„ 62-37

Long.

63-37

j • • •

„ €4-37

i»

Medium-long,

„ 65-37

„ 66- 37

Long.

67-37

Medium-long.

„ 68- 37

1 Long,

69-37

i ii

2. Henrietta Experiment Station.

Blur Stir/, Variety * — Selections of this variety made from the 1930
Autumn Crop were established in progeny rows during the 1937 Spring Crop.
Four strains selected from these were put in a Strain trial (see page 86) with the
ordinary Blur Stick , but results showed no significant difference in yield.
Progeny Rows were still maintained in the 1937 Autumn Crop, and now there
are under test twelve selections of this variety.

Local hug grains . Because of the demand in Essequibo for long-grained
types of padi, selection work was begun in the 1937 Spring Crop. Progeny rows
of various padis were established, and now there are under test the following ; —

Varieties Under Test at Henrietta Experiment Station.

Variet >’ rewived.

No. of

Origin. seasons

tested.

Type of Grain.

LI 1936

L3 < „

L5 1937

L6 „

Affiance 2

Aberdeen 2

Spring Garden 2

Wakenaam 2 1

Hampton Court ( —

Johanna Cecilia 1 —

L’Union —

Long.

Medium-long.

...

*4*

AGMCtfLttfRAL J&URltAL OP SftlTlStt GUlANA.

‘[IX, 1

Indian Padi. Daring the 1937 Antamn Crop progeny rows were establish-
ed of a sample of padi received from Messrs. Seymour and Sayse Narayan, who
imported it from India. The sample was very mixed, and before planting was
arbitrarily divided into classes based on grain lengths. Selections were further
made at the end of the crop, so that now there are 26 selections of this padi
under test.

PROGRAMME OF WORK FOR 1938.

1. Variety Trials.

Fourteen variety trials will be laid down in 1938 in selected sites of the
Colony. These are as follows : —

The first six trials will be carried out at Georgetown, Henrietta and Whim.

A. Standard Long Grain Trials.

I. 5 Randomised Blocks.

II. 5 Randomised Blocks.

1 . Padi Berbice

2. D251

3. D253

4. D254

5. D259

6. Jaisingh

7. Demerara Creole

8. Kalyaman

9. D114 \

10. D99 )

L. G. Controls.

M. G. Controls.

1 .

2 .

6 .

8 .

«).

10 .

D221

Nickeric Patna
Seymour S.

No. 13-37
No. 29-37

D91

Demerara Creole
Kalyaman

L. G. Controls.

| M. G. Controls.

B. Standard Medium Grain Controls.

III. 5 Randomised Blocks.

1. D94

2. D108

3. Unity

4. D162

5. D193

6. D109

7. Demerara Creole j L G Controlg .

O* DmwI I

10.' D99 4 ^ M - G - Coutr,,l8<

IV. 5 Randomised Blocks.

1. D258

2. D261

3. D262

4. No. 15-37

5. No. 16-37

6. DUO

7. Demerar, Creole j L „ C(ml „ ) | a .

10.' M9 4 I M ' 0o “ lr<>U -

RSsOlts of fAbi Varietal trials.

9ft

V. 5 Ramdomiscd

1. D246

2. D247

3. D250

4. D255

5. D256

6. D257

7. D116

Blocks. VI.

1 .
2 .

6 .

L. G. Controls.

10 .

8. Demerara Creole |

9. D221 )

10. D114 )

11. D99 j

M. G. Controls

5 Randomised Blocks.
No. 17-37
No. 18-37
No. 19-37
No. 23-37

Blue Stick.

D115

Demerara Creole J L G. Controls.
]• M. G. Controls.

The remaining trials are individual district trials and are distributed in the
various localities mentioned.

C. Individual District Trials.

VII. No. 63 (Shied Trial)

5 Randomised Blocks.

1 . Demerara Creole

2. No. 79

3. D99

4. D114

5. D115

6. D116

7. Babylon No. 1

8. Benab No. 1

9. D97 (B)

10. Benab No. 79

IX. W. C. Berbice (site to be selected).
5 Randomised Blocks.

1. D114

2. Demerara Creole

3. Kalyaman

4. D99

5. No. 79

6. D116

7. D110

8. D115

9. D221

VIII. W.C. Berbice (site to be selected).
5 Randomised Blocks.

1. Demerara Creole.

2. No. 79

3. D99

4. D114

5. D115

6. D116

7. Babylon No. 1

8. Benab No. 1

9. D97 (B)

10. Benab No. 79.

X. Henrietta. Long Grain

XI. Trials with D114 as control. To
be drawn up after results of
Spring Crop.

XII. Georgetown. Long Grain

XIII. Trials With D114 as control: To

be drawn up after results of
Spring Crop.

100 AGRICtri/rukAL JOUfeNAL Ofr BRITISH GttlANA. [iX, 2.

XIY. Vreed-en-Hoop

5 Randomised Blocks.

1. D114 (control)

2. D99

3. DUO

4. Kalyaman

5. Demerara Creole
tl. D115

7. D116

8. Seymour S.

0. Jaisingh

2. MISCELLANEOUS TRIALS.

The trials to determine (1) the optimum age for transplanting seedlings
(2) the optimum number of seedlings per hole have not as yet given any con-
clusive results. Those trials will be continued at Henrietta during the 1938
Autumn crop.

3. DEMONSTRATIONS.

In the districts certain varieties are being grown for demonstration pur-
poses. These demonstrations can be seen in the named localities.

District.

Site.

Variety.

Area.

W.C. Berbioe

To bo selected

5 acres

Abary District

No. 7!)

2 „

East Demerara

No\ar.

No 711 and

D W

Glazier’s Lust

No. 79

80 „

Co\e & John

D114

5 „

East Bank, Demerara.

To be selected.

D114

U „

No. 79

1] „

West Demerara.

La Grange.

D114

3 „

Fellowship.

D114

Vreed-cn-Hoop.

D114 &

DC.

f» „

„

Manurial experiments are also being planned in conjunction with the
Chemist and will be laid down both at the Georgetown and Henrietta Experi-
ment Stations.

THE VARIETY AND FERTILISER POSITION OF THE
SUGAR INDUSTRY, IV.

C. HOLMAN B. WILLIAMS, m.a., a.i.c.t.a., dip. agr„

Sugar Agronomist and Plant Breeder,

ESTATE YIELDS IN 1937.

The Department of Agriculture is again indebted to the Managers of the
Colony’s sugar estates for kindly supplying statistics of the commercial yields
secured during 1937. The date are condensed and presented in Table I. In
Table II are given the weighted mean yields of the three principal varieties for
the past four years.

The outstanding conclusion to be drawn is the marked superiority of
P.O.J. 2878 to its nearest rival, Diamond 10, on frontland soils. Large acreage 8
of both canes have now been reaped, as plants, first and second ratoons, in several
seasons and throughout the sugar belt, and it is clear that P.O.J. 2878 may be
expected to yield, for a cycle of three crops, over a ton of sugar per acre more
than Diamond 10. The latter is, however, a decided improvement on D. 025.
On the pegasse soils, the differences are less marked, but P.O.J. 2878 continues
to head the list. ‘‘Mixed ” areas, S.C. 12/4 and B.H. 10/12 should be eliminated.

Table I.

WEIGHTED MEAN YIELDS OF 96" SUGAR PER ENGLISH ACRE FROM THE MAJOR
VARIETIES GROWN IN BRITISH GUIANA DURING 1937.

Frontland Soils, Pkoasse soils.

PO.J.

2878

Diamond

I io

D 625^

Mixed

S.C.

12/4

B.H.

10/12

P.O J.
2878

Wmond D

Mixed

1 Acre*

Plant .
( ’anes

reaped •

\ Yield ol
HUgHr/acre.

1,906.5

j 6,908 7

2.170.8

152.0

3< 5.U

67.1

1,810.3

*1.780.7

343.7

I ,

\ -

VUmn

3.811

3.42

2.04

2.83

* 3.40 1

3.34

3.20

2,5)2

FlTHt 1
Rat- 4

( AcreH

2.227.2 |

reaped
Yield ot

5.819.1

4,008 1

086.6

240.2

51.2

001 6

1,350 0

1 66; «

104.5

221

oons |

1 MURnr/ucre.
'-tons

3 78|

I 3.00

2.97

2.21

2.85

267

3.10

2.82

1 2.70

2.03

2.71

Second 1
Rat- 4

f At*re<<

reaped •

1 Yield ot

1,079.5 (

4.241-1.1

(1,331.3 ,

1,018.2

235.7

18 h

706 3

832.3

932.7

407.3 |

48.6

oon» |

HUgar/acre,

'tons

3.01 !

3.23 |

2.02 1

2.2C

2.62

2.36

2.63

2 44

3.12

2.0l!

1.17

Three

'Total

- 1

j -

—

Yield of

CropH

RUgar/acre.
.torn. :

11.20

9 .05

n. 12 !

7.14

8.30

8.43

0 13

8.55 1

8.83

102 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 2.

Table II.

WEIGHTED MEAN YIELDS OF 96° SUGAR PER ENGLISH ACRE FROM THE MAJOR
VARIETIES GROWN IN BRITISH GUIANA DURING 1934-1937.

Frontland Soils. j

Pegasse Soils.

P.O.sl.2878

[Diamond 10l D. 625

P.O.J.2878

Diamond 101

IX 625 _

Plant I

^ Acres reaped :

8,707.4

22,050.8

24,654.5

3,480 2

3,110.1

2,525.4

Canes j

Yield of sugar
i per acre, tons :

' 3.94

355

3.38

325

3.43

3.51

First

j' Acres reaped :

3,971.1

17,082.4

29,755.8

1,818.3

2,091.7

3,7569

Batoons ’

Yield of sugar
^per acre, tons :

3 76

308

3.00

3.16

2.95

2.81

Second j

^ Acres reaped :

1,462.1

11,418.1

27,533.6

860 6

1,324.1

3,373.5

Batoons 1

I Yield of sugar

Iper acre, tons :

3.25

3 04

2.67

2.71

2.46

2.70

[Total Yield of

Three J

sugar per acre,

9 12

8.84

Crops i

.tons .

10.95

9.67

9 05

9 02

VARIETAL COMPOSITION OF THE 1938 HARVESTS.

The estate Managers have also kindly furnished data from which it has been
possible to prepare Tables III and IV and Figure I, showing the relative import-
ance, by area, of the varieties to be harvested in 1938.

Table III.

PERCENTAGE DISTRIBUTION OF THE VARIETIES TO BE REAPED DURING 1938.
( Varieties listed represent 100% oj the total area to he harvested.)

Variety.

Diamond 10
P.O.J. 2878
D. 625
Mixed
S.C. 12/4
Miscellaneous
B.H. 10 (12)

Total English
Acres in the

^Percentage
in West

Percentage

along

Demerara

(Percentage
in East

Colony. )

Demerara.

River

Banks.

26,356.08 (41.3%)

22.3

39.3

20,228.99 (31.7%)

13.5

6.8

13,140.72 (20.6%)

• • •

2.6

2,537.31 ( 4.0%)

16.8

44.5

996.46 ( 1.6%)

48.3

43.1

324 33 ( 0.5%)

3.9

34.4

170.08 ( 0.3%)
63,753.97 (100.%)

73.3

9.5

Demerara.

17.1
32.6
34.9

0.1

1.2

15.2

17.2

Percentage

Berbice.

21.3

47.1

62.5

38.6
7.4

46.5

PLATE IV.

WEST DEMERARA EAST DEMERARA

Fig. I.

Relative Varietal Composition of the Cane Areas to be harvested in British Guiana in 1938.

Table IV.

TfiB VARIETY AND FERTILISER POSITION OF THE SUGAR INDUSTRY, IV. 103

a a a h 8

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104 AGRICULTURAL JOURNAL OF BRITISH GUIANA. tlX, 2.

The replacement of D. 625 by Diamond 10 and P.O.J. 2878 is progressing
rapidly and only 21 per cent, of the acreage is now in the old favourite. On
the other hand, P.O.J. 2878 is now expanding much more rapidly than Diamond
19 and will probably soon pass it. “ Mixed ” areas continue to drop. These
points are brought out in Table V.

Table V.

CoMPARIHOV OF AREAS OF D. 625, DIAMOND 10, P.O.J. 2878 AND “MIXED”
IN THE COLONY DURING RECENT YEARS.

Variety.

Per Cent, of Total Area

in the Colony.

1934 |

1935

1936 i

1937

1938

D. 625

62.5

55.4

44.6 !

33.0

20.6

Diamond 10

16.8

22.7

29.4

36.6

41.3

P.O.J. 2878

4.7

9.7 1

19.2 1

31.7

“Mixed”

“ !

12.6

12.7

8.8 1

4.0

Diamond 10 and P.O.J. 2878 occupy 89 per cent, of the cane area in West
Demerara and 85 per cent, on the Demerara River Banks, but in East Demerara
and Berbice, D. 625 still covers 29 and 33 per cent., respectively, of the area to
be harvested.

The item “miscellaneous” includes mainly new seedlings which are being
tested commercially. More areas could, with advantage, be devoted to thin
purpose all over the Colony, but especially in West and East Demerara.

FERTILISERS IK 1937.

In Table VI, the fertiliser imports for 1937 are compared with those of
recent years, the data being adapted from the Reports of the Comptroller of
Customs.

*hb Variety and Yertiuiser position of the sugar industry, iv. lflS

106

AGRlCULUfatAL JOURNAL OF BRITISH GUIANA.

[IX, 2.

Imports of sulphate of ammonia, which have shown a tendency to rise
throughout the twelve-year period, reached a record of 11,171 tons In 1937.
Its cost per ton has been climbing slightly since 1934. Imports of manurial
lime (mainly pulverised limestone) were considerably higher than in 1936 and
well above the twelve-year average ; its cost is dropping. Slightly less “ other
fertilisers ” were imported than in 1936 and the cost per ton was a few cents
lower.

All the Bulphate of ammonia came from the United Kingdom and all of
the manurial lime from the British West Indies (Trinidad and, to a lesser extent,
Barbados). Of the phosphates, 77 per cent, came from Belgium, most of the
rest from Holland and a small quantity from Germany. The potassic manures
came almost exclusively from Germany.

Of the money spent for fertilisers, some 77 per cent, goes for sulphate of
ammonia, 15 per cent, for phosphates and potash, and 8 per cent, for limestone
and lime.

More than 95 per cent, of the fertilisers imported are used on the sugar
estates and much of the remainder by small cane farm°rB. The estates have
kindly supplied details as to the various manures used in 1937 and the data are
summarised in Tables VII and VIII and Figure II.

In 1937 the estates spent 79 per cent, of their fertiliser bill on sulphate
of ammonia. The imports of lime have shown a further drop in favour of
limestone which is easier to handle and cheaper.

Fig. II.

Relative Quantities and Values of Fertilisers used on British Guiana Sugar Estates in 1937*

THE VARIETY AND FERTILISER POSITION OF THE SUGAR INDUSTRY, IV. 107

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AGRICULTURAL JOURNAL OF BRITISH GUIANA.

◄

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Total

* [IX, 2#

SELECTED ARTICLE

EDTBLE COCONUT OIL*

REGINALD CHILD, F.I.C., B.Sc\, pu.D. (Lorn)

( Director of Research and Technological Chemist ,

Coconut Research Scheme ,)

Refined coconut oil, either alone or in admixture with similar fats such as
Palm Kernel and Babassu Fats, has been sold for edible purposes in Europe and
elsewhere under a wide variety of trade or proprietary names. Among the best
known of these (some of which are still protected by registration) are Cocolardo,
Cocoline, Lactine, Laureol, Nucoline, Nutrex, Nutto, Palmine, Vegetaline and in
India, Messrs. Tata’s well known Cocogem. As generic names for this type of
edible fat have been used, Nut Lard, Vegetable Lard and Vegetable Butter.

It has been pointed out that reference to these preparations as “ Vege-
table Butters ” (and similarly in German “ Pflanzenbutter, ” and in French
“ Beurro de coco ”) is unfortunate, since in temperate climates they are pure
white, odourless and tasteless edible fats, which are not plastic and contain no
milk constituents as do butter and margarine. In Ceylon and the tropics gener-
ally coconut and similar oils are liquid and this point does not arise, since the
word “ butter ” will not in auy case be applicable.

The present article has been written since many inquiries have been received
by the writer on the possibility of the local preparation and marketing of an
edible grade of coconut oil. Some analytical figures obtained in connection with
such inquiries are included.

Standards of Edible Coconut Oil.

Up to any point short of severe rancidity any coconut oil could in a sense be
described as edible. Cheldiu oil, which may contain up' to 2 per cent, of free fatty
acid and may bo of dark colour and strong odour, is consumed locally, but
would by no means be reported by an analyst as of “edible grade”. Indeed for
edible coconut oil used as such and in the manufacture of margarine, stringent
standards have been laid down. For example a Committee of Analysts to the
Ministry of Food in Great Britain in 1919 required “ fine ediblo coconut oil ” to
contain less than 0.1 per cent, of free fatty acid (as lauric), not more than 0.5
per cent, of moisture or 1 per cent, of unsaponifiable matter. The oil has also to
be free from suspended impurities, and sweet and neutral in taste and odour.
American authorities also lay down limits of colour; viz., not more than 12
yellow and 2 red units on Lovibond’s Equivalent colour scale.t

•Reprinted from the “ Tropical Agriculturist ” of Ceylon, Voi 89, No, 5, November 1937.
tThis is net the same scale as referred to by the British Standard Specification,

110

AGBTCULTUBAL JOUBNAL OF BBIT18H GUIANA#

[IX, 2.

The oil further has, of course, to comply with standards laid down
for coconut oil of any grade, <>.$., in the case of the British Standard
Specification, the refractive index at 40°C. must be between 1*4485
and 1.4492, and the iodine value between 7.0 and 9.5, whilst the saponification
value should not be lower than 255.

Commercially, oils of such high grade have almost always been subjected
to processes of refining.

Refining Processes.

For the purposes of the present article it is unnecessary to give
details of commercial refining processes, but it will be as well to mention
the principles involved. It will be dear that to convert, say, a copra oil of
ordinary mill grade to a refined oil meeting the specifications outlined above,
four main stages of purification are necessary ;

(a) Filtration or sedimentation to remove suspended impurities.
Under this also may be included treatment to remove mucilagi-
nous impurities which may escape removal by filtration.

(b) Removal of free fatty acid by means of alkali treatment.

(dj Deodorization.

Industrially, free fatty acid is almost always removed by means of caustic
soda in slight excess ( about 0.2 per cent.) of the theoretical amount. After the
soap so formed has been removed the oil is washed and dried, and the decolor-
ization or bleaching treatment follows. This is effected by treatment with
activated charcoal and/or fuller’s earth, folio sved by filtration* In the last stage
the oil is treated in a vacuum apparatus with superheated steam which causes
the odoriferous constituents to be distilled off. Technical details of this last
operation are often strictly guarded as trade secrets.

On an industrial Scale these opeiations require complicated plant and tech-
nical control at all stages. Such plants do not, of course, exist in Ceylon and it
is extremely doubtful whether any potential demand exists sufficient to encour-
age anyone to invest capital in refining plants.

Small Scale Refining.

It is possible to refine a crude oil to a large extent by small scale methods.
For example, the Department of Industries, Madras, has published a bulletin
describing simple methods of refining oils, mostly devoted to describing the
removal of free fatty acid by means of such alkaline reagents as lime, soda and
silicate of soda. Bleaching with charcoal and/or bleaching earths can be adapted
to a smkll scale and improvement of odour achieved, as is indeed done with
CheJihu oil, by simple boiling with water. <

EDIBLE COCONUT OIL.

Ill

Refining Losses.

On such a small scale, however, refining losses are considerable. A. 1\ Lee
of the India Refining Co., Philadelphia, published in 1924 an interesting
account of coconut oil refining. The losses in refining an oil of f.f.a. (lauric)
2.58 per cent, colour (Lovibond scale) 35.1 yellow, 5.85 red, to an oil of f.f.a,
0.08 per cent., colour 4.01 yellow, 0.51 red, amounted to 6.1 per cent, of which
5.5 per cent, was removed as acid oil for soap stock. On a small scale the losses
are vastly in excess of this.

Domestic Preparation of Oil in Ceylon.

It is doubtful whether there is any necessity to attempt to give instruction
in refining coconut oil to the local villager. When small quantities of a good oil
are required they are prepared locally by the domestic method which will be
familiar to local readers.

The usual well-known proceduie is to grate the fresh kernels using the
ordinary domestic scraper or hiramanai found in every Ceylon household. The
grated meat with added water (about a pint to a nut) is hand squeezed and the
resulting emulsion strained. A second squeezing after adding more water is
usually given and even a third treatment by boiling with water and again
squeezing. The emulsion of oil and water is boiled down until all the water is
removed and clear oil is finally poured off from the caramelized residue.

The oil yield is naturally low in comparison with that of commercial ex-
pression of oil copra, and attempts to produce oil on a large scale by a modification
of this process both in Ceylon and elsewhere have met with little success. An
English Patent (No. 10,601/1914) claimed “ a process for the extraction of oil
from the coconut and other nuts, consisting of reducing the kernel or flesh of the
nuts to small pieces, adding water to about the bulk of the flesh and well mixing,
subjecting the mixture to a process of grating, collecting the essential cream of
the flesh produced thereby and laying the same on sieves and subjecting it to
pressure to precipitate the essential cream of the flesh and water, Ac., Ac.”
Plant is described for carrying out these and subsequent operations, which
are seen to resemble closely the hand methods described above. This process
does not appear to have been worked successfully.

Parker and Prill in the Philippines in 1917 found that when freshly
grated coconut meat was pressed at 1,000 lb. per square inch, over 60 per cent,
of oil remained in the cake. By treating the material with water and steam 80
per cent, of the oil could be obtained by pressing, it being found best to separ-
ate the oil by chilling the emulsion to 60°F.

80 per cent, of the oil present seems to be about the best yield obtainable by
hand pressing and it will be noticed that the domestic use of water and boiling
to get further oil from second and third squeezings agrees with the results of
Parker and Brill's scientific investigations. Six nuts are reckoned loyally to
give a bottte of oil (about 670 gms.) and a trial under the writer’s supervision

11? AGRICULTURAL JOURNAL OF BRITISH GUIANA, [IX* 2,

gave from six nuts 760 gms., the nuts being of a size which would have given
about 000 gms. of oil if converted into copra and hydraulically pressed,

The oil obtained in this trial was yellow in colour, with a strong but sweet
odour of the nut, and f.f.a. (lauric) 0.12 per cent. It is referred to as No. 4 in
the table and the oil from a similiar trial as No. 3. Such oil is fairly satisfac*
tory in keeping properties ; indeed the scientific literature contains some
reference to it from this point of view. Lewkowitsch, for example, in his
Standard work states that “ if the oil is prepared from fresh kernels by boil«

ing (as is done on the Malabar coast and to some extent in Ceylon) it

undergoes little change. ”

Manufacture of Oil From Fresh Kernels Rapidly Dried.

Since it is very unlikely to be economic to erect refineries in Ceylon, and
since the domestic method of making an edible oil does not seem likely to be
successfully adapted to a larger scale, the question arises whether any other
method suggests itself for preparing coconut oil of edible grade without the
necessity of refining.

The only likely method, which has been tried twice on a fairly large scale
is to disintegrate fresh kernels in the same way as is done in the preparation of
desiccated coconut, but without removing the brown skin ; to dry the disinte-
grated kernels in desiccators to the usual D.C. standard and at once to express the oil
from the product*. The oils so obtained had the analytical characteristics given as
Nos. 5 and C in the table. They were not completely odourless, though nearly so,
and had a bland taste but otherwise would be regarded as up to the edible grade.
For local sale it is possible that less stringent standards would be necessary as re-
gards odour — a slight sweet odour and taste of coconut might not be objected to.

This oil was sold at tho ordinary price of White Oil as there was no special
demand for oil of a special grade in small parcels. Retail sale was not, however,
attempted.

Analytical Figures, Abnormal and Otherwise.

The table of analyses summarises results obtained on various samples
submitted by enquirers, some of whom have attempted small scale refining methods,
and special methods ot preparation (of which the writer has not always been
informed). Other figures lrom the literature are given for comparison. It will
be noticed that some samples give abnormal figures for iodine and saponification
values and for refractive index. In these cases it is not suspected that the sam-
ples have been adulterated ; to obtain a waterwhite oil, the samples have in many
of these instances been prepared from the white meat only. It is well known that
“ paring ” oil obtained as a by-product in desiccated coconut manufacture has an
average iodine value much higher than that of ordinary oil, a lower saponification
value and density, and a higher refractive index. Correspondingly, oil from the
white meat, or pressed from desiccated coconut, has a lower iodine value and
refractive index, and a higher saponification value.

Oifuz and West of the Philippines reported an analysis on white oil fron$
desiccated coconut, with the results shown as No. 10 in Table I, t

tJDlBLfi COCONtrt 6IL,

113

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not up to f
edible j
grade par-
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on account
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IM M

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114

AGRICULTURAL JOURNAl OF BRITISH GUIANA,

[IX, 2.

In the case of domestic oil the scraping stops somewhat short of including
all the brown parings, so that these oils show iodine values slightly less than
ordinary oil, but not so low as those from the white meat only.

The percentage of unsaponifiable matter has not been determined on the
samples reported here. At one time it appears that paraffin wax er heavy paraffin
oil has been added to coconut fat (in temperate climates) to give it a consistency
more resembling butter. The latter found in a sample of “ vegetable butter,”
3.9 per cent, of unsaponifiable matter of iodine value 2.05, saponification value
O, refractive index 1.475 at 4(UC. The writer has examined a similar paraffin
oil, which, it was stated, was used as an addition to edible oils. This had iodine
value 2.3, saponification value 0.2. refractive index 1.465 at 40°C. Such
additions are unlikely in Ceylon ; to liquid oils there would be little point
in them, and as mentioned above, they have not been looked for in local samples.

Coconut “Stearin” and “Olein”.

Edible coconut oils of various melting points are obtained by the process
known as "winterising". By pressing the partly solidified oil at various
temperatures it is separated into higher and lower melting portions, the pro-
portions depending on the temperature and pressure. The higher melting
portions are referred to as “ coconut stearin ” and the lower as “ coconut
olein ”. The aqalytical constants of these will lie respectively on each side
of the average values for ordinary oil. Bolton gives the following usual
limits, but mentions that “ there are manufactured products made in a great
variety of melting points, according to the extent of pressure, and only the very
extreme figures are given, and practically all commercial samples yield figures
well between these limits ”.

' Coconut Stearin. Coconut Olein.

Melting point °C.
Incipient fusion
Complete fusion
Solidifying point °C.
Saponification value
Refractive Index 40°C

Iodine Value (Wijs)
Sp. gravity 1*9°/15°0

F.f.a. (laoric)
Reichert-Meissl value
l’ol^pske value

Usual

Limits.

20—31

24—29

252—235

1.4483—

1.4487

2—7.9

0.800—

• 0.809
0.2— 5.0
4.5— 0.0
8.0-15.0

Typical

specimen

(refined).

29 |

30 I

27.4 1

252.1

].448Cj

4.1

0.860

0.1

5.0

10.7

Usual

Limits.

10—22
14-22
257-262
1.4492—
1.1494
1 1—15
• • •

3.13

8.10

17—20

Typical

specimen

(refined).

23.5

19.1
258.3

1.4493

14.2
0.870

0.2

9.2

•Approx, from Zeiss butyro-refractometer readings

fcblBLE COCONUT OIL.

115

A. P. Lee gives interesting particulars of the working of this process
and describes a large scale trial in which the oil as described above was kept be-
tween 12.5 — 15.5°C. for 40 to 60 hours and then pressed, there being obtained 38.2
per cent* of hard butter or stearin of solidifying point 26.68°C* and 00.95 per
cent, of olein of S*l\ 20.3°(\

It will be apparent that some care has to be exercised in interpreting the
analysis of edible coconut oils. Oils from the white meat only have low iodine
values like “stearin,” but whereas the former tend to have saponification values
above the average, the reverse is true of the latter. Similarly the iodine values
of “olein” (above the average for ordinary oil) may approach those of commercial
parings oil, but the latter have saponification values well below the average for
ordinary oil, whilst 44 oleins ” are about the average or a little above. Coconut
“stearin ” is more used indirectly for edible purposes than directly, as a
substitute for cacao butter in chocolate and confectionery.

Hydrogenation.

Coconut oil can be hardened by the process of hydrogenation. The melting
point can be raised to about 44.r»°C, when the iodine value is reduced to 1 0.
The saponification value is not greatly altered.

EcONOM 1 c C( >NS1 DER A T IONS,

Whilst coconut oil hardened by hydrogenation and high melting coconut
Stearin might be useful in the tropics as edible fats for cooking, etc., it is very
unlikely that the processes for their manufacture could be economically worked
in Coylon. Enquiries are occasionally received by the writer asking for details
of such processes — particularly hydrogenation — to which the reply is generally
made that the processes require extensive plant and expert technical management*
and that there is little likelihood of their inception locally.

It is said that whilst it is true that local demand would not justify an edible
oil industry, there is a possibility of an export business. This is, in the writer’s
opinion, also unlikely. Neighbouring countries are all themselves oil (and
particularly coconut oil) producing countries. India in particular already
protects her oil crushing industry by a heavier duty on oil than on copra.
Many European and other countries w beie refining inteiests exist put a heavy
tariff on edible grades of oil, whilst admitting unrefined oil at lesser rates.

Any attempt at retailing edible oil in Ceylon is likely to remain a small-
scale business, and the oil either prepared by the simpler method outlined, or
refined by methods applicable on a small scale*

Vitamins in Coconut oil.

Whilst there is some evidence that coconut oil in its fresh state contains
Some vitamin A and vitamin 1‘i, it is not a good source of any vitamin, and
vitamins are unlikely to be present at all in the refined oil. Home manufacturers
therefore add vitamin preparations and a well-known proprietary brand in

116 AGRICULTURAL JOURNAL OF BRITISH GUIANA. £lX, 1

India is stated to contain added vitamin D. Vitamin preparations can bo
purchased from pharmaceutical houses, but their local preparation or use is not
likely to become a possibility of interest, the object of health authorities being
more to ensure that the local dietaries contain sufficient vitamins in other
natural foodstuffs used.

Addition of Flavouring Matters.

Flavouring matters have been added to refined coconut and other oils.

As recently as 1929 it was shown that the substance responsible for
the aroma of butter is diacetyl. This has been added to margarine in small
traces to imitate the odour of butter and its use in edible coconut and other fats
has been tried.

Other Modifications.

Processes have been devised to render coconut fat plastic so as more to re-
semble lard or butter in texture. The fat is submitted to processes of foaming
with air or carbon dioxide and of kneading to the required consistency. These
do not in the ordinary way apply to the tropics where the fats are liquid oils.

Keeping Qualities.

The oldor text-books on oils and fats used to mention coconut oil as one of
the most susceptible to rancidity. This was true of the inferior copra oils
formerly shipped, but as mentioned above oil prepared from fresh kernels or
any oil initially sound keeps well, as do well refined oils, particularly in air-
tight containers protecting the oil from light and air.

The stringent standards laid down have the keeping quality of the oil in
view as well as its initial soundness.

The use of preservatives such as bensioic or chloroben/.oic acids or of anti-
oxidants should not be necessary, particularly in an oil intended for quick local
Consumption.

Summary.

The present article reviews the processes used commercially in the prepara-
tion of coconut oil of edible grade, and mentions the modified forms under
which such oil is marketed. From the local point of view the opinion is expressed
that large-scale refining and other processes are unlikely to be worked in Ceylon,
as there is Unlikely to be an extensive local demand and the possibilities of
export are doubtful for tariff and other reasons.

The preparation of coconut oil suitable for edible purposes locally on a
smaller scale for retail marketing may be possible ; processes are suggested for
producing an initially sound oil needing no refining, and mention made of the
possibility of small-scale refining.

Analytical reports on samples of various kinds examined in the writer’s
laboratory are tabulated, and some figures from the literature given for com-
parison,

NOTES.

Boron in Agriculture.— In Research Bulletin No. 5 (West of Scotland
Agricultural College Plant Husbandry Dept.), R. W. G Dennis and 1). G. O’Brien
draw attention to the part played by boron in agriculture.

The interest in boron as a component of lield crops arose in 1910, when
•Agulhon published results of Held tests, in which he obtained increase in dry
weight of 50 per cent, for maize, 21 per cent, for colza, and 32 per cent, for
turnips, as a result of applying 0.5 grammes of boron (as boric acid) per square
metre. Yet there was no proof that boron is essential for plant growth until
Brandenburg in 1931 demonstrated that boron deficiency occurs in the field,
and is the underlying cause of dry-rot in sugar beet and mangolds. Boron
almost immediately took its place in the list of accepted fertilizers.

Boron in this Soil.

Although boron is an essential component of some 5f> minerals, the majority
of these are rare or of restricted occurrence, and the only widespread member
of the group is tourmaline — a boro-silicate of aluminium and iron. It is doubt-
ful, however, if t mrnuline forms a source of boron available as plant food, as it
is resistant to weathering, but its occurrence in the Held in rocks or soils may
he an indication that boron deficiency is unlikely in that area. On the other
hand, tin' comparatively high boron content of sea water Jed to the suggestion
that the boron content of soils and rocks is derived from the sea, and thus clay
soils of marine origin are usually adequately supplied with this element.

Boron Deficiency in Some Tropical Crops.

Suf/ttr Symptoms of boron deficiency in sugar cane grown in

water cultures have been described in detail by Martin, who employed cuttings
of the Varieties 11 109, T.O..J 30, P.O.J. 2878, Yellow Caledonia and Badila, pre*
viously rook'd in black volcanic sand.

The most marked effect of boron deficiency was the retardation of growth,
Usually, after one or two months the first definite symptoms developed as minute
elongated watery spots on the young leaves. These lesions elongated parallel
to the vascular bundles and resulted in a striping of the leaves. Older lesions
exhibited p dark red centre surrounded by chlorotic tissue, and, finally, fracture
of the dead tissue occurred. Young leaves w f ere short, narrowed at the base,
and chlorotic, with irregular brown edges. The symptoms also included en-
largement of the lower cells of the bundle sheath in the leaves, sometimes so
marked as to cause the formation of elongated gall-like bodies on the lower leaf
surface. The^ bundle fibres were poorly developed ahd lacked the normal silica

118 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [l% k

content. Martin remarks that the symptoms observed in his cultures very
closely resemble those of Pokkah-boeng disease of sugar cane, associated with the
fungus Fmarium moniliformc Sheldon, and suggests that the severity of this
disease is related to the degree of boron deficiency in the sugar cane plant.

Rice, In a series of pot cultures in a weakly aoid clay soil Tokuoka and
Morooka showed that a concentration of 20 parts per million of boron was toxic
to the plants. Larger quantities of boron led to extensive growth of Gladm-
porium on leaves and grain. Later they reported that minute doses of boron
increased the number of grain-bearing stems per plant and raised the yield of
grain. Optimum growth was secured at a concentration of 0.4 parts per million
of boron. They concluded that boron was not essential for the growth of rice,
but did not determine the pre-existing boron content of the soil used.

Citrus : Haas and his fellow- workers have shown that in sand culture,
boron to the extent of 0.2 parts per million of the culture solution is essential
for the normal growth of citrus. The deficiency symptoms are summarized^ as
follows: “Leaves curled along the midrib with the tip of the leaf curling
downward ; leaves coloured a brownish or yellowish green, often with a yellow-
ing along the midrib; midrib or veins conspicuous, corky and split; and a pro-
gressive loss of affected leaves in the basi petal direction. In severe cases there
is a tendency towards “multiple bud ” formation due to new twigs dying when
barely visible. When the bark of the internodes of the twigs, or in severe cases,
that of the trunk, splits, au amber coloured gum oozes out. Eventually the
cracks may widen so that the woody tissue is exposed. In severe cases the
apical portion of the branch dies back. The roots become dark brown in colour
and fail to elongate and in advanced cases the rootlets decay. On adding a
suitable concentration of boron to the culture solution the symptoms of decline
disappear”.

Maize : The evidence so far available indicates that little advantage can
be expected to accrue from the application of boron to maize.

Tobacco t ]VrMurtrey found in water culture experiments that the
effects of boron deficiency were usually apparent within a week or ten days of
the transferring ot a plant to a nutrient solution lacking this element. The
first visible effect was the manifestation of a light green colour of the leaves
making up the bud, with the base of the individual leaf assuming a lighter
green than the tip. When this appears, the bud has ceased to grow and has a
Somewhat drawn appearance. This is followed in a day or so by the breakdown
of the tissue at the base of the young leaves making up the bud.

In the Deli district of Sumatra a disease called topziekte of tobacco occurs
which corresponds for the most part with those of boron deficiency, and the
addition of boric acid at the rate of 3 milligrammes per plant was effective in
great% reducing the incidence of this disease. It was later found by Meurs that
applications heavier than 6 milligrammes per plant would probably be toxic*

KOTfiS.

lii)

in 1935 M’Murtrey described the occurrence of boron deficiency, as exemp-
lified by the death of the terminal bud and crinkling of the upper leaves, in field
plots laid down on sandy soil in Maryland, tJ.S.A. Boric acid was applied at the
rate of 5 lbs. per acre and completely prevented further development of the
disease.

Cotton : By means of sand cultures carried out on a large scale in the
open Eaton has shoun that boron is essential for the normal growth of cotton.
Plants grown without sufficient boron became stunted, the leaves were buckled
and irregular in shape, and most of the flower buds and young bolls were shed.
A concentration of 1 part per million of boron was sufficient to suppress the
marked deficiency symptoms, but the largest plants and greatest number of bolls
were obtained with a nutrient solution containing 10 parts per million, although
signs of toxicity were visible at this higher concentration. Analysis of the
plants showed that boron is accumulated mainly in the leaves and Eaton estimat-
ed that as much as 10 lbs. borax per acre per annum might be removed from
the soil.

Tomato * The symptoms of boron deficiency in tomato are death of the
growing points of shoot and root with stimulation of development of secondary
roots and axillary buds, together with thickening and curling of the leaves.
Internal symptoms include brown discoloration of the cell walls, enlargement of
the phloem, and deformation of some of the thin-walled tissues. The tissues of
the flower stalk also degenerate and the flowers die prematurely.

In Johnston and Fisher’s experiments, approximately four times as many
fruits set on plants supplied with boron as on boron-free plants. On the latter
the fruit were covered witn darkened or dead areas due to the breakdown of
the cells.

D.W.D*

New Ornamental Plants introduced into the Botanic Gardens during
1937. — The Gardens are much indebted to the Arnold Arboretum of Harvard
University for a large selection of seed of ornamental plants, some of which
yielded very welcome innovations. Besides a number of species of Aristolochia,
which flowered in the Rockery and nearby, * there were several new shpubs,
including Domheya Mastersii, and Strobilanthm isophylhu >*, which latter made
a good showing opposite the bandstand and elicited several enquiries as to its
identity. A smell Erythrina — E. Sencgalensis — bloomed profusely at the end of
the year, and more plants of it have been set out.

Apart from # the usual purchases of seed of annuals and perennials for the
borders, and a few new rose plants, other introductions from seedsmen and
nurseries included a large collection of dahlias from Holland, which attracted
considerable attention when they were in bloom, a new species of Lonicera
(L. TeUemanniana\ which has not yet been put out, and a pretty pale fhauve
Achimenes which has flowered well in the Rockery*

120 AGRICULTURAL JOURNAL OP BRITISH GUIANA. [IX, t.

A correspondent in Florida, with whom plants have been exchanged, sent
us a good selection of Amaryllids, most of which however, have not yet matured
gnffioiently to flower; one or two Amaryllids were also obtained from another
correspondent in Sonth Africa.

From Bermuda we received a new purple variety of Salvia, which flowered
well in the borders, and has already found its way into some gardens in the
town, a yellow Buddleia, which has yet to flower, and some Arum Lily seed.

Some palm seed came to us from Porto Rico, and to another friend in
Florida, we were much indebted for seed of an ornamental bamboo, Dendro-
calamus at rictus.

E. B. M.

Legislation. — As a reminder to the public, attention was drawn in Depart-
ment of Agriculture notice No. (>93 to new legislation introduced into Trinidad
affecting the importation of plants.

The importation into Trinidad of cacao plants and cacao beans from this
Colony is prohibited. A certificate of origin stating that the following fruits
and vegetables have been imported into British Guiana must be submitted before
importation into Trinidad is allowed : pineapples, yams, sweet potatoes, tanniae,
eddoes and dasheens. Plants, seed, cuttings and fruit of citrus, sugar-cane,
bananas and cocmubs may be imported into Trinidad only if a permit from the
Director of Agriculture of British Guiaua is obtained.

An Order-in Council under Section .‘1 of the Plant Diseases and Peels
(Prevention) Ordinance, 193.">, prohibits the importation into this Colony of
Grapefruit from Trinidad and of all citrus fruit from the other islands of the
British West Indies.

British West Indies Fruit and Vegetable Councils —The first joint meeting
nf the Eastern and Western Group Councils and the third meeting of the Eastern
Group Council were held at the Imperial College of Tropical Agriculture,
Trinidad, from February 9 to 15, I DBS. The chief recommendations are : —

Recommendations.

i. Grapefruit.

Reoommondations 1 and 2 of the West Indian Intercolonial Fruit and
Vegetable Conference (Jamaica) 191)3 relating to grapefruit and manges are
endorsed by this meeting with the exception that it is recommended that future
plantings of grapefruit should be restricted to the seedless varieties.

It is also recommended that further extensions of grapefruit planting
Sh&tld only be undertaken with caution and after careful consideration of the
present world position.

NOTES.

2. Mangoes.

Recommendation No. 5 of the West Indian Intercolonial Fruit and Vegetable
Conference (Jamaica) 1933 concerning mangoes is endorsed by this meeting but
it is noted with regret that the absence of suitable and frequent shipping facilities
among the Colonies of the Kastern Group makes development of a profitable
trade problematical. It has also been noted that the Canadian market offers
little prospect of development for this commodity.

3. Avocado Pear a.

This meeting while endorsing Recommendation No. fi of the West Indian
Intercolonial Fruit and Vegetable Conference (Jamaica) 1933 concerning avocado
pears desires to draw attention to the need for further experiments with West
Indian and other varieties in order to provide the planting fublic with tjprs
suitable for export.

4. Pineapple*.

This meeting endorses Recommendation No. 7 of the West Indian Inter-
colonial Fruit and Vegetable Conference (Jamaica) 1933 concerning pineapples
and finds that as there has been no improvement in the position regardiog either
fresh or canned pineapples there appears to be no object in carrying ont
extensive experimental work with this crop at present.

5. Pooling of Information.

The meeting has given consideration to Recommendation No. 10 of the
West Indian Intercolonial Fruit and Vegetable Conference (Jamaica) 1933 con-
cerning the pooling of information and finds that normally there is insufficient
material for the regular publication of a bulletin of the type referred to in that
Recommendation and considers that the Councils of the Eastern and Western
Groups should arrange for the circulation of information as it becomes available.

'fi. Marveling Intelligence Offirei .

This meeting notes with satisfaction that the Eastern Group Trade
Commissioner in Canada has undertaken many of the duties which would fall
upon a marketing Intelligence Officer such as was suggested in Recommendation
No. 1(1 of the 1933 Conference and that Jamaica has made an appointment of a
development and Marketing Officer whose functions are of a similar nature. It
is also noted that the Bermuda Government has established the necessary
machinery for keeping in touch with Canadian markets.

In these circumstances this meeting feels that the appointment of a whole-
time West Indian Marketing Intelligence Officer in Canada is at present
unnecessary but recommends that the closest contact should be maintained
between the Eastern Group Trade Commissioner, the Marketing Division in
Jamaica and the Department of Agriculture in Bermuda. .

7. Oo-operation between citrus marketing organisations.

This meeting having arranged a joint meeting between the Co-operative
Citrus Growers’ Association of Trinidad and Tobago and the Dominica, Jamaica

122 AGRICULTURAL JOURNAL OF BRITISH GUIANA, [IX, 2

and British Honduras delegates recommends that the closest contact should
be maintained in the future between the official citrus marketing bodies in
Trinidad, Jamaica, Dominica and British Honduras with a view to the establish*
ment at a later date of a West Indian Citrus Fruit Exchange.

8. Re-establishment of an official agricultural department in Bahamas ,

This meeting records with satisfaction the efforts of the Bahamas towards
the institution of more orderly methods of marketing tomatoes and suggests
that it is desirable that estimates of acreage and production of this crop in the
Bahamas should be made available as early as possible for the information and
guidance of other producing Colonies. It is therefore hoped that the Govern-
ment of the Bahamas will find it possible to re-establish the official agricultural
department.

9. Bananas .

In view of the great importance of the banana as a cash crop in many of the
Colonies of the Eastern Group this meeting recommends that every endeavour
should be made to stimulate further production,

10. Banana breeding .

In view of the progress which has been made in breeding varieties immune
to Panama disease and Cerrospora leaf spot this meeting strongly recommends
that early steps be taken to provide the geneticists engaged in banana breeding
with wild varieties of bananas necessary to serve as suitable parents for the pur-
pose of breeding, as soon as possible, an immune variety with suitable commercial
characters, •

11. Low Temperature Research Stations .

This meeting recommends that the officers of the Low Temperature Stations
in Trinidad and Jamaica should collaborate in drawing up a schedule of optimum
storage temperatures at which West Indian fruit and vegetables should be trans-
ported and that this schedule should be revised when necessary in the light of
further investigations. It is further recommended that the attention of shipping
companies serving the West Indian area should be drawn to the necessity for
adopting these temperatures as standards.

12. Measures designed to control spread of Diaprepcs spp.

This meeting recommends that all fruit, vegetables and ground provisions
for export to Colonies where the weevils ( Diaprepes sppJ are not known to
exist from any country or countries where the weevils (Diaprepes spp .) are
known to exist must be accompanied by a certificate issued by a Government
Inspector in the country of origin to the effect that the produce is reasonably
free from foliage, trash and soil.

13. The Anglo-United States and the Canada-United States Trade Agreements .
This meeting desires to draw the attention of the Secretary of State for the

Colonies and the Canadian Go verment to the serious effects on the British West
Indian fruft and vegetable industries which have resulted from the Canada-

HOTBS,

123

United Stated Trade Agreement. These effects have been most marked with
citrus and miscellaneous vegetables other than tomatoes'

It is noted with satisfaction that the continuation of the Canadian Preference
on British Colonial tomatoes has been ensured through the Trade Agreement
between the United Kingdom and Canada. A rednction or abolition of this
preference would result in a serious setback to the tomato industries of the West
Indian Colonies. The continuance of this preference is therefore essential.

Through the abolition of the tariff on American oranges from January to
April in each year the West Indian trade in this commodity has received a severe
blow, since the peak of Jamaica production is in late December and January.
An extension of the protected period for West Indian oranges in Canada to include
the month of January is therefore most desirable and this additional month could
be exchanged for an even longer period of free duty for American oranges in the
summer months apparently without any present damage to Empire trade in the
commodity.

It is hoped to institute an advertising campaign in Canada for British West
Indian limes, but with the existing ad valorem Intermediate and General
Canadian tariffs on this commodity the West Indian Islands have little protection
from foreign competition. It is therefore desirable that, in the interests of these
Colonies, the Canadian Government be asked to amend the tariff on foreign
limes to a specific duty of 2c. per lb.

It is further recommended that the assistance of the Secretary of State for
the Colonies be sought to represent the desirability of concession being given to
West Indian limes and lime juice entering United States in the Anglo-United
States Trade Agreement, negotiations for which are now proceeding.

14 Empire preference on cifru* fnnt entering the United Kingdom.

This Meeting having given consideration to reports of the possibility of the
general rate of duty on citrus fruit on importation into the United Kingdcm
being reduced, recommends that the attention of the Secretary of State for the
Colonies be drawn to the disastrous effects which such action would have upon
the growing British West Indies citrus industry which was developed "largely
upon the recommendation of an expert who visited the West Indies in 1928 at
the invitation of the Empire Marketing Board, a policy of development which
was later confirmed by the Secretary of State following the receipt of the Report
of the West Indian Intercolonial Fruit and Vegetable Conference convened by
the Colonial, Office and held in Jamaica ip 1933 : the meeting further recom-
mends that the Governor of Trinidad be asked to forward this recommendation to
the Secretary of State for the Colonies by telegram and that the memorandum of
the Trinidad Chamber of Commerce Inc. which is fully supported by representa-
tives of all the British West Indian Colonies and the Jamaica Imperial Association
be forwarded by airmail.

134 AGRICtTfcmAL JOURHAt OP BRITISH OUUHA. tlX, 3,

15* Preference* for British West Indian fruit and vegetables in Canada and
the United States of America.

This meeting views with regret that the abolition or reduction in Canadian
preferences on West Indian vegetables has made trade in these commodities
much more difficult and it is felt that the British West Indies have a fully
Justifiable claim to consideration by the United States for concessions, even if
seasonal and for a limited quantity, on vegetables, citrus and other fruits enter*
hr* the United States in return for the concessions granted to the United States
of America by Canada.

The approaohing negotiations for an Anglo-American Trade Agreement
offer a suitable opportunity for putting forward these claims, and it is hoped that
the Secretary of State for the Colonies will arrange for the fullest representation
on behalf of the British West Indies.

16, Freight Bate 9,

This meeting notes with alarm recent increases in freight rates which have
been coincident in most instances with a reduction in commodity prices and
desires to seek the assistance of the Secretary of State for the Colonies in watch-
ing the interests of these Colonies in regard to freight rates. The meeting also
hopes that Canadian National Steamships will maintain their sympathetic attitude
towards producers in the West Indian Colonies and find it possible to remove the
increases recently instituted in the Eastern group.

17. lime Grower * Associations and a West Indian Limes Association,

This meeting notes with satisfaction the successful foimation of a West
Indian Lime Oil Sales Company and recommends that lime oil producers in
Colonies not yet affiliated to that Company should give favourable consideration
to such central marketing organizations.

It is apparent that farther progress in the marketing of limes and lime
products can only be satisfactorily developed and extra production allowed for
by means of centralised advertising directed through a joint West Indian associa-
tion of lime growers and other lime interests. This meeting therefore strongly
recommends the early formation of Lime Growers Associations in all the West
Indian Colonies concerned to be followed by tho formation of a West Indian
Limes Association with the constitution recommended at the meeting of lime
growers representatives held at the Imperial College of Tropical Agriculture on
February 12th, lflfiN.

This meeting farther recommends that this West Indian Association when
formed should tuke steps to obtain the co-operation of lime interests in the
Gold Coast.

It is farther recommended that all West Indian lime producing Colonies
should institute a system of export cesses or other contributions to provide funds
for the West Indian Limes Association on the basis of fid. per lb. on distilled lime
oil, Cd. per lb. on ecaelled lime oil, fid, per barrel on greon limes and Id. per gallon
on top pulp juHe exported.

NOTES.

125

This meeting also notes that Recommendation No. 3 of the West Indian
Intercolonial Frnit and Vegetable Conference (Jamaica) 1933 relating to limes
and lemons has not been followed by certain lime growers and while it does not
appear practical to prohibit farther plantings yet it is felt that the dangers of
over-prod notion are now more apparent than they were in 1933.

18. Utilization of the services of the Colonial Marketing Board.

This meeting strongly recommends that the possibilities shonld be explored
of the means of utilising the services of the Colonial Marketing Hoard for the
benefit of the Wc3t Indian fruit and vegetable industries, and that the collaboration
of other bodies such as the West India Committee and the Canadian West Indian
League should besought to work with the official marketing services in the Colonies
as well as the two Croup Councils.

This meeting farther recommends that the Commissioner of Agriculture,
Imperial College of Tropical Agriculture, and the Development and Marketing
Officer in Jamaica should be requested during their visit to the United Kingdom
during the summer of 1 938, to seek the assistance of the Agricultural Adviser
to the Secretary of State for the Colonies and the Colonial Marketing Board in
regard to expanding the markets for limes and lime products.

19. United action by Colonial Governments.

This meeting recommends that the Governments of the Colonies represented
at this meeting should unite in making representations to the Secretary of 8tate
for the Colonies and other Governments on subjects of general importance relating
to the frnit and vegetable industries although this should not preclude individual
representations on matters more directly concerning a particular Colony.

Organisation of Intercolonial Trade in Fruit and Veoktarles.

Arising out of the discussion on various trade matters, the view was
expressed by Professor Dash that the time had arrived for the careful investiga-
tion of the Intercolonial trade in fruit and vegetables from the commercial as
well as the quarantine aspects. The Conference fully endorsed this view. It
was suggested that a Committee should be appointed to investigate conditions of
the trade. The proposal is that each Colony should be asked to give an idea of
the seasons of their main fruit and vegetables and the likely expoitable surpluses
for intercolonial trade. Such information would form the basis of possible trade
agreements between the various Colonies, with a view to preventing competition
of looally-grown produce with imported commodities of a similar nature. By
careful regulation periodic gluts would be avoided and better prices ensured to
producers cs a,wholo. It would also help to make these Colonies self-supporting
in regard to Caribbean grown fruit and vegetables.

NEWS,

His Excellency the Governor, accompanied by the Director of Agriculture,
visited the economic farm unit at Toevlugt, West Bank, Demcrara, on Thursday,
April 21.

His Excellency also visited the Central Offices of the Department on
Wednesday, Juno 15.

Sir Geoffrey Evans, Principal, and Mr. E. McC. Callan, Lecturer in
Entomology, of the Imperial College of Tropical Agriculture, visited the Colony
with a party of post-graduate students from April G to 15. These tours have
become a regular feature and enable students to obtain first hand knowledge of
the Colony’s agricultural and forest industries and its economic problems. Such
intercourse cannot but be of advantage to all concerned.

Mr. G. Milne, M.Sc., F.I.C., Soil Chemist to the East African Research
Station, Amani, visited the Colony from April 8 to 11). Advantage was taken
of this visit to discuss the different aspects of the soil and agricultural problems
of the Colony.

Dr. D. S. Fernandes, Director of the Department of Agricultural Economics,
Paramaribo, Suriname, paid a visit to the Department on April 19. It was a
veiy welcome opportunity for exchanging views with Dr. Fernandes, especially in
connection with the curing of Liberian coffee, a subject to which he has given
considerable Btudy.

Dr. Sant, Government Analyst, also of Paramaribo, visited the Department
on May 13.

Dr. A. C. Smith of the New York Botanic Gardens, who had accompanied
the Terry-Holden expedition to British Guiana, visited the Botanical Division
of this Department on May 13 and 16. Dr. Smith made a large collection of
plants in the Rupununi District, specimens of which are being sent to Kew.

Another visitor from New York was Judge Jacob Panken, who arrived on
June 14.

The Director of Agriculture was on tour in Berbice from March 28 to April
1 and in Esseqfuibo from April 30 to May 4.

NEWS,

127

Daring the period ander review the Deputy Director of Agriculture paid
visits of inspection to Anna Begins, Leguan, the banana experiment and
economic farm settlement on the West Coast Demerara and to rice areas on the
West Coast Berbice and the Corentyne.

The Botanist and Chemist visited the North West District, leaving George-
town on April 2.1 and returning via Pomeroon on May i>. While in the district
they inspected the Department’s station and sub-station at Hosororo and Wanna
respectively and visited a number of the chief landholders and farmers, with
whom they discussed various matters of agricultural interest. In addition, a
number of small grants were visited.

Major Thomas Bone, O.B.E., M.R.C.V.8., Government Veterinary Surgeon,
left the Colony on 4 7/30 months leave prior to retiring. Major Bone joined
this Department in 1028 after seeing army service in England, Ireland, France,
India and Italy. After retiring from the army, the Major served for one year
with the British South Africa Company, afterwards in Rhodesia, and became
Chief Veterinary Officer to the Compania de Mozambique, Portueuese East
Africa. He acted as Senior Veterinary Officer in South West Africa (Mandated
Territory). Major Bone has served in British Guiana for about 10 years during
which time a considerable enlargement in scope of the Department’s livestock
investigations and activities has taken place, the benefits of which can only
be fully felt as time goes on. Results are, however, already apparent in the
case of dairy cattle, especially in the areas adjoining Georgetown. His col-
leagues wish him every good fortune in his retirement.

Mr. James I). Gillespie, B.Sc., Agricultural Superintendent in this Depart-
ment from January, 1030, has been promoted to the post of Agricultural Officer,
Sierra L**one. Mr. Gillespie is at present stationed in Berbice and will leave for
his new post in August next.

Officers of the Department who have already left or who will shortly be
leaving the Colony on vacation are: Capt. F. Burnett, Deputy Director of
Agriculture, L. D. Cloire, Entomologist, Major T. Bone, Government Veterinary
Surgeon, C. H. B. Williams, Sugar Agronomist, H. E. H. Gadd, Rice Grading
Officer, Miss V. Chan-Choong, Librarian.

During the absence of Major Bone and Mr. Gadd, Mr. H. A. Fraser, B.V.Sc.,
and Mr. H. D. Huggins, Agricultural Superintendent, have been appointed to
act as Government Veterinary Surgeon and Rice Grading Officer, respectively.

.128 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX. 2.

The Report of the Committee which was appointed to enquire into matters
affecting the rice indnstry was published as Leg. Oo. Sessional Paper No. 1/1938.
Mr. Percy W. King, Crown Solicitor, was Chairman, Oapt. F. Barnett, Deputy
Chairman and Mr. H. E. H. Gadd, Secretary,

His Excellency the Governor has been pleased to appoint a Committee to
report on the advisability of establishing a central rice mill on the Esseqnibo
Coast for the purpose of affording relief in that area.

A meeting of the Board of Agriculture was held at the Head Office, Depart-
ment of Agriculture, on March 21 and a meeting of the Sugar Experiment
Stations’ Committee was held on June 13,

PLANT AND SEED IMPORTAf 10^.

Introdactions by the Department of Agriculture for the period
March — May, 1938.

Name

Quantity.

j Whence Supplied

Economic.

Asstd Vegetable Seed

17i 02.

H, 0. Hastings & Co., U.S.A.

Cutting*, 12 cane varieties

of each

Plant Quarantine S t a t i o il
T rimdad.

Derr is e! I i plica ,

cuttings

St. Augustine Nursery, Trini-
dad.

Maize— I.C.M. 1

lb.

I.C.T.A., Trinidad.

I.C.M. 3 and 4

lb. each

do.

Mahogany Seeds !

lb. ■

Dept, of Agriculture, Tiinidad,

Nutmeg Seods

500

do.

Soya Beau j

lb.

I.C.T.A., Trinidad.

Ornamental.

Col villea mveinnm

OZ.

Dept of Agriculture, Trinidad,

Irctthtc ? er$choffeHu

plants

do.

iS 'air in far inured var. alba

pkt, sood

do.

BruvfeUia inti da

Calfixtemon speeiaons

I hi her ft a si hhoo

Erf /I hrtna bevteronia na

Lifsiloma sabian

Veltophorum braMilieunr

)■

pkt. i uch

Secretary for Agric. Est avion
Exptl. Agronomic », Cuba.

Colnhiina Jerruginea

oz.

do.

Anthurium Lilies

plants

Eden Flower Shop, Trin’.dad.

Dahlias (asstd )

bulbs

Papcndroelit Vandervoet, Sas-
senhoim, Holland.

Boses

plants

^ H. G. Hastings & go., U.S.A.

ltoses (Double White Killarney)

plants

i Peter Henderson & Co., New
York, U.S.A.

Swoot Bens

pkts.

! do.

Violet Tree |

pkt,

j Mayaguez Expt. Stn., Puerto
Hico.

MEtEOfeOLOGICAL DATA— JANAURY TO MARCH, 1038.

Rooording Sta ions &
Months.

Rain-

fall.

j _ OS

|JS

Botanic Gardens.

January

1334

February

1510

March

13.70

Totals

42.20

Means

Berbice Gardens,

January

February

March

10.55

15.90

15 G7

-5

Totals

Means

42 21

Onderneeming.

January

15 43

February

9-30

March

21 GO

Totals

4G f 2

Means

Hoiororo,

North West District

January

11- 43

February

10-25

March

14-03

Totals

35-71

Means I

fctfRR&frT HtCtS 6t COLONIAL PRODUCE

From The Commercial Review , Journal of the Georgetown Chamber
of Commerce , Vol. XXI , No. 5 , Tuesday , 31st May , 2955 .

SUGAR.

Per 100 lb. net 3 lb. per Bag allowed for tare

Dark Crystals for Local Consumption 13.30

Yellow Crystals do. do $4.00

White Crystals $4.75

Molasses Sugar none offering.

Above Prices include Excise Tax of 90c.

RUM.

Imperial Gallon. Cask included.

Coloured, in Puncheons — 40 to 42 O.P...(for export). ..60c.; Hhds. 52c., Barrels 77c

White, in Hogsheads— 40 to 45 O.P...(for local consumption) 45 to 55c

MOLASSES.

Per Imperial Gallon. Naked.

Yellow (firsts) 10c.

Yellow (seconds) 5ic.

RICE.

Rice per Bag of 180 lb. gross. Brown Super $4.00 to $4.25 ; No. 1, $3.75—

$3.90 ; Wh'te, Non? available. Lower Grades $3.25 — $3.65 as to quality
Padi per Bag of 143 lb. gross, $1.20 as to quality.

GENERAL.

Gold, Raw,... average per oz. $26 to $27.

Diamonds,— pro rata as to quality average per carat $10 to $11.

Timber, Greenheart, (Lower grade measurements) . . .40c.- to 60c. per c. ft. ;

for export 72c. to $1.00 per c. ft.

do. Railroad Sleepers — (Mora) $l,fi8each.

Greenheart Lumber $70 to $80 per 1,000 feet.

Crab wood Lumber $60 to $75 per 1,000 feet.

Shingles, Wallaba, 4 x 20 and 5 x 22 inches,.... $4.50 to $6.00 per M.

Charcoal, Capped for shipment 72c. to 85c. per bag.

Firewood $2.50 per ton.

Coconuts... Selects, $9.00, oulls $6.00 per M... Copra $2.00 per 100 lbs. prime Copra.

Balata Venezuelan, none. Local Sheet. ..36c.' to 38c. per lb.

Cocoa M ....19c. to 19ic. „ „

Coffee ..4|c. to 5c. „ „

N.B.— Duty Payable on value at time of Importation and rate of exchange on day of
arrival.

m * , ^ . a

I nC tCK lAINiT g

OF DAWN. 1

in quiet confidence*— |
and in the adherence |

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to sound business prin- |

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true success. The Royal |

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Bank offers to legiti- 1

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security and prestige |

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which sixty-six years of ?

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ROYAL BANK:

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f ARE IN A CLASS BY THEMSELVES FOR DRIVING- j

DRAINAGE PUMPS

m 2

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| and other Machinery connected with Agriculture. §

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] The Demerara Electric Company, Ltd. !

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| Headquarters for Electrical Supplies. 1

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Vet. IX, No. 3.

September, 1938.

The

Agricultural Journal

British Guiana

PUBLISHBD BY

' THE DEPARTMENT OF AGRICULTURE,

GEORGETOWN, BRITISH GUIANA.

Pric*

•e
• •

•l

6d.

DEPARTMENT OF 'AGRICULTURE.

ADMINISTRATION

Director of Agriculture ...

Deputy Director

Clerical

Senior Clerk
Registrar of Banks

Class III Clerks

Probationers

Librarian

RESEARCH BRANCH.

Botany and Plant Pathology

Botanist— Plant Pathologist and Superintend-
ent , Botanic Gardens :

E. B. Martyn, B.A., A.I.C.T.A.

Technical Assistant :

N. Persaud

Chemistry

Chemist :

D. W. Duthie, M.A., B.Sc., Ph.D., F.I.C.
Assistant Chemist ;

C. L. C. Bourne

Entomology

Entomologist :

L. 1). Clear©, F.R. Ent. S. (on leave)
Technical Assistant :

O. Williams

Rico

Assistant Plant Breeder :

P. A. Chan-Choong, B.Sc., A.I.C.T.A.

Sugar

(In co-operation with the Sugar Producers)
Sugar Agronomist and Plant Breeder :

C. H. B. Williams, M.A., AXG.T.A., Dip.
Agr. (on leave)

Laboratory Assistants :

H. B. Singh

A. V, Wan-Ping, Dip. Agr.

Statistical Clwhx
J, B. Bourne (on leave)

... Prof. The Hon. J. Sydney Dash.
B.Sc, (Agric.)

••• £• Burnett, M.C., M.A. (on leave)

E. M. Peterkin (acting)

SUff.

J. F. Irving, M.C.

W. G. Delph

A. A. Thorne
Miss D. M. Terrill

Miss M. Cheong
P. 0. Jackson
••• s 8. A. Adams
Miss R. Delph
' Miss S, Lord

Miss Y. Chan-Choong (on leave)

LIVESTOCK BRANCH

Veterinary Surgeon :

,T. Bone, O.B.E., M.R*C.V.S. (on leave)

H A Fraser, B.V Sc. (acting)

FIELD BRANCH

Agricultural Superintendents'.

Be rbice— (Vacant)

Demerara, East— E.M. Peterkin
Demerara, East Bank— H. D. Huggins,
M.Sc., Dip. Agr.

Demerara, West— E. G. Benson, B.Sc.,
A.I.C.T.A., Dip. Agr.
Essequibo-A. A. Abraham
Assistant Agricultural Superintendent:

Berbioe— E. M. Morgan
Agricultural Instructors :

Botanic Gardens— H. A. Cole

( C. C. Dowding, F.L.S.,
Demerara, East—] F.R.H.S.

I G. L. Leitch (acting)
Demerara, East Bank— I. Dewar (acting)
Essequibo— A. W. Sears
North West District— L. E. McKinnon
Berbice— O. F. J. Chnraman, Dip. Agr.
Agricultural Assistants:

Demerara, East — J. Indrobeharry
Berbice— H. B. France *

Sugar

Field Manager (Centred Station J
C. Cameron
Field Assistants :

L. A. Forte
B. A. McArthur

branch

Technical Assistant :

D. D. Blackman

/ -

Meteorological {Assistant :

' f.iUt-

«ps mum . ps*b

Grading Inspector:

EL E. H. Gftdd (on leave)

H. B. Huggins (acting)

Technical A»si*tant» : * ‘ *

V. A. Bovell (acting)
ft. ft. Boss

ADVISORY BOARD OF AGRICULTURE

Director of Agriculture, Chairman, officio*

Deputy Director of Agriculture, Vice-Chairman, eac q#eto.

Hon. Peer Bacchus

Hon. R. £. Brassipgton . fM •••

Hon. J. W Jackson 7 ,

Hon. F. J. Seaf ord, o*B.a

Mr. 8. Andries
n B. B. Hunter
„ W. H. Richards

Members

SUGAR EXPERIMENT STATIONS COMMITTEE.

Director of Agriculture, Chairman, ex-officio.

Hon. M. B G. Austin, o.b.e.

Mr. H F: Chapman (acting for Mr. G. M. Eccles)...
„ J. C. Gibson «•>

„ A. Munson ... ... ...

„ R.R. Rhodes

„ J. Bee * ...

Georgetown
Pin. Bath
Pin. Port Mourant
Pin. Uitvlugt
Pin. Diamond
Pin. Albion

\ Representing
I the Sugar
• Industry

i which wain*
I tales the
/ Statlees

CO-OPERATIVE CREDIT

Director of Agriculture, Chairman, ex-officio .

Hon. J. W. Jackson
Rev. A. 13. Dyett ...
Mr. C. Farnum ...

„ J. L. Wills ...

BANKS’ BOARD.

Members

DISTRICT AGRICULTURAL COMMITTEES

EAST DEMERARA

Director of- Agriculture, Chaiiman
District Commissioner

Deputy Director of Agriculture
Hon. J. I. deAguiar -

Hop. £. M. Walcott
Mr. 8. Andries ...

,, M. Ghani
W. H. Richards
„ J. E. Wills ...

Members

Director of Agriculture, Chairman
District Commissioner

Deputy Bltectof of Agriculture
Hon. J. W. Jackson
Dr. the Hon. J. B. Singh
Mr. R. P. Carryl * ...

J.C. DaSilva •

„ ILkB. Hunter .1.

„ A. Murison ...

„ W. Ramdeholl ..*

„ A. Bayman ...

WEST

' «.t

DEMERARA

Members

CONTENTS.

(VOL. IX, No. 3.)

Page

EDITORIAL— 133

ORIGINAL ARTICLES.

Malaria in British Gaiana,

Part II. ... . Q. (jrighoh. M D. (If.), M R.C.P. ( Land .),

D.T.M. <1 R. (Eng.) ... ... 135

Coconnt Wilt in Esseqnibo

and Pomeroon Districts ... T). IF. Duthie, Ph.D , I.I.O. ... 147

A Grade Dairy Herd ... H. A, Fraser, B.V.Sc. ... ... 153

A Milling Test on Sixty

Padi Varieties ... ... I). IF. Duthie, Ph.D., F.IC. and

C. L. (\ Bourne. ... ... 163

SELECTED ARTICLE.

The Cultivation of Cajanus
Cajan and the methods of

* preparing marketable Dhal ... P. M. Gaywala, M.Ag. ... ... 169

REPORT.

Fifteenth Meeting of Advisory

Board of Agriculture ... ... ... ... ... 178

NOTE.

Padi and Rice Production

in India and Burma ... ... ... ... ... 183

NEWS , ... ... ... ... ... 190

PLANT AND SEED IMPORTATION ... ... ... 191

METEOROLOGICAL DATA

CURRENT PRICES OF COLONIAL PRODUCE ... ... 193

Contents— Continued.

ILLUSTRATIONS

Facing Pag®

Plat®

I.— Fig.

4 — Random sample of A. darlingi captured
in houses in the Tillage of Rampoor,
(Blairmont).

144

Plate

II. — Fig.

5 — Random sample of A. albitarsis caught
in houses in the same village.

145

Plat®

III. — Fig.

1— “ Orchard Leigh Heilborn Mercedes.” A
purebred Holstein Friesian Bull owned
by the Department of Agriculture.

156

♦♦

,,-Fig.

2— “ Candies Carbine.” A purebred Guern-
sey Bull owned by the Department of
Agriculture.

156

Plate

IV. — Fig.

3— A Grade Holstein-Creole Herd. ...

157

»»

,, —Fig.

4— Grade Holstein-Creole Calves, 10-12
months old, reared on a commercial
calf meal feed.

137

Plate

V.-Fig.

1— Apparatus for Steaming Padi.

164

Plate

VI.— Fig.

2 — Experimental Mill. ... ...

166

Plate

VII.— Fig.

3 — Close View of Grader, ...

168

The

Agricnkoral Journal of British Guiana.

September, 1938.

EDITORIAL*

ECONOMIC STOCK-RAISING.

In a report on a visit to Palestine and the Trans-Jordan, the Agricultural
Adviser to the Secretary of State for the Colonies pointed out that 44 the improve-
ment of flocks is unlikely to be permanent until attention is given to feeding,

for it has now been recognised that the class of animals which a country possesses
depends upon the class of feeding which is provided.” This statement expresses
concisely what is now accepted as a universal truth. It is being shown beyond
question that the limiting factor to bigger and better livestock industries in
British Guiana is the problem of cheap, balanced feeds. Thus, in the case of
cattle in this Colony, the grazing in general is relatively poor and the pasturage
is seldom regarded as a crop requiring drainage, cultivation, irrigation and the
application of fertilisers ; but the cattle-owner cannot be too severely censured
for this since the land on which his cattle graze is seldom his. Most of the
lands rented for pasturage are grazed on the communal basis, and there has thus
been in consequence little inducement for the individual to undertake the
necessary expenditure for fencing and paddocking. Without fences and
paddocks good pastures become poor and poor pastures become poorer.

The significance of this pasturage problem in regard to the development of
a cattle industry has been receiving much attention by the Department's Live-
stock and other Divisions ; the feeding value of the Colony’s herbage has been
studied on the Government Stock Farm and elsewhere, and it has been found
that for the most part our fodders are deficient in lime and phosphate, but, in
individual cases, contain considerable quantities of these constituents; by
Judicious admixture nutritive and palatable feeds are being obtained. Some of
the fodders used in these trials and giving promising results, include Demerara
Primrose, Guinea grass, Para grass, Wynne grasS, Guatemala grass, Horse
Weed, Teosinte and Iruhgofera endecaphylla.

In an article in this number (“A Grade Dairy Herd”), are disof&sed the
problems which are being faced in building up a dairy herd of good stock and
maintaining satisfactory production in regard to quality and quantity. This
herd has been run on a purely commercial basis and the passages on 44 Feeding-
Staffs” and 44 Pastures” will well repay attention.

The points, which thus far have been taken, are discussed both to show the
dependence'of our biggest livestock industry — cattle— on the supply of suitable
feeds and to indicate some of the steps which are being taken to achieve
improvement ; but it is not only in the cattle industry that feeds play this
dominating part. The same holds good for poultry, and in this industry much
importance is attached to this aspect ; thus, when recently a series of meetings
was held 4o consider the organising of a bigger local poultry industry, the ease
for balanced rations at cheaper prices was given an early hearing. At one of these
meetings, convened by the Director of Agriculture on September 5, the chief
item discussed was the formation of a Poultry Association together with the aims

134 AGRIC0 1/f tTB AL JOVBlXkt, Ot URttlSfi GtttAlU, [iX* 3.

and policy of snob an Association. Now that the air hi clearing in respect to
local agricultural industries, sugar, rice, livestock, and with the increased
activities of Government in connection with importations of improved types*
there is a growing trade in live poultry and eggs. Encouragement in this
direction is being provided by recently improved steamer connections
between Berbice ports and Trinidad so that shipments are now being made
from Berbice and other ports of the Colony to that market. For these reasons
it seemed desirable to organise an Association of some type which conld, in
collaboration with the Department of Agriculture, exercise a watching brief over
the industry, consider its needs, and undertake measures calculated to be of
benefit to the movement generaJly.

It is accepted that, because of a number of factors such as the high cost of
feed, the low prices of eggs and poultry, and the absence of an outlet for surplus
production, poultry activities have in the past been somewhat fitful. Of these
factors the most important is the absence of a locally produoed and sufficiently
cheap, balanced ration. Progress has, however, been made within recent years
since it is now possible to import into the Colony, free of duty, certain feeds high
in protein content. It is understood that the Demerara Meat Company which
slaughters a good deal of the stock for consumption in Georgetown has in process
of erection equipment suitable for turning out a cheap xfetioa high in animal
protein and processed from blood and animal refuse. Feeds of the starchy type
can be obtained iii abundance locally ; coconut by-products can be useful.
In a country such as British Guiana, where rice is extensively grown, it would
appear reasonable that by-products from this crop should be available to form
the basis of a good ration. Up to the present, however, the rice milling systems
which are in operation have, in general, found it difficult or impossible to recover
the valuable rice by-products (e.g., rice bran, etc,,) and to make them available
for animal consumption. Plans are now under consideration for the establish-
ment of modem rice milling units. Apart from the direct benefit to the rice
producers, centralized up-to-date mills will be able to separate by-products which
will then be available in such quantity and quality as to make the outlook for all
forms of stock more favourable.

Another aspect of the feeding question will be a more general cultivation
of peas and beans for use in poultry feeds ; these are rich in proteins and
although farmers have in recent years undertaken the cultivation of blackeye
peas on a much more extensive scale, much can yet be done. Appreciation of
the fact by farmers that peas and beans might, in addition to cash sales, be
converted into poultry and eggs and sold as such, should serve as a further
inducement for the inclusion of more of these crops in the regular farming
routine.

An important factor which should be considered by those going into
poultry-keeping as a business is whether or not the size of the enterprise
embarked upon is large enough. Work done in many poultry-rearing districts
has consistently shown that an influence of considerable importance in deter*
mining raofit or loss in the poultry business is whether or not the minimum
number 61 birds is being kept. When the number of birds kept is too small*
the cost of supervisiotii feed, and sanitation make profits difficult if not
impossible.

With a better outlook for feeds and with the organisation of an active
poultry msoeiation, the possibilities are brighter for building up poultry-rearing
into a minor but promising industry.

ORIGINAL ARTICLES.

MALARIA IN BRITISH GUIANA.

PART II. WHICH OF THE LOCAL ANOPHELINE SPECIES ARE
RESPONSIBLE FOR THE TRANSMISSION OF MALARIA ?

G. GIGLIOLI, m.d. (It.), m.r.c.p., (Lord.) ; d.t.m. & h. (Eng.).

Medical Adviser to the Sugar Estates of British Guiana.

We have seen that three species of Anopheles, A. tarsbnaculatus, JL albi-
tarsis and A. darling i, exist in this Colony in large numbers and with a wide
distribution.

All of these are known as malarial vectors in other regions of Tropical
America : A. tarsi inaculat us is a carrier in Panama and Trinidad : Kumm
(1932) at Bahia, in Brasil, found A . albitarsis abundant in houses and 5.8% were
infected with malaria; A. darling / is now recognized as the principal and
most dangerous carrier in Brazil, from the Atlantic to the Andes, throughout
the Amazon basin and in Venezuela ; more recently, it has been found in French
Guiana.

All these three species are susceptible to infection when made to feed on
suitable malaria patients. We have ourselves had no difficulty in producing such
artificial infeetions. These experiments are by no means conclusive as
incriminating evidence, as the conditions which are created in the laboratory do
not necessarily subsist iu nature.

In the present section we propose to lead what evidence we have been able
to collect concerning the relative importance of each ohe of these mosquitoes in
relation to the transmission of malaria in this Colony.

(I) Geographical and Topographical Distribution op Malaria
in thk Colony, and its Relation to the Distribution
op the Various Anophelinb Species.

There is, no part of the Colony, on the coast or in the interior, which can
be said to be entirely free from malaria. Concerning the incidence and the
distribution of this disease it is necessary to bear constantly in mind that
malaria infection can remain latent for weeks and months. The infection may
not become apparent till long after the patient has left the locality where he
contracted it. We have known cases which suffered their first attack in Europe
several moifths after leaving the Colony.

MALARIA IN BRITISH GUIANA,

137

The occurrence of & few cases of malaria in any one given place, therefore,
by no means implies that the disease was acquired on the spot and that the
locality must be regarded as malarial.

In this connection the frequent displacement of the population from one
district to the other, in search of work, must be considered. The gold, diamond,
bauxite and timber industries keep a constant flow of men between the coast
and the highly malarial districts of the interior. Cane cutting and rice planting
and reaping again cause frequent seasonal displacements of the population along
the coast and on the smaller rivers (Mahaica, Mahaicony, Abary and Canje).

Apart from these well defined, regular and, more or less, constant or
seasonal currents, one must not forget the ordinary displacement due to business
or pleasure as, for instance, the prevailing custom, amongst East Indian women
and children in particular, of “ passing time ” with relations or friends on other
estates or in villages. *

We will now outline briefly the methods currently employed for measuring
the incidence of malaria.

The Parasite index of a locality or community is given by the percentage
of children, under 12 years, habitually residing in that locality, which actually
harbour malaria parasites in their blood. This is a direct method of measure-
ment giving exact data on the actual rate of infection at the time of the survey.
Recent and acute infections naturally are the most easily detected.

The Spleen index shows the percentage of children which present enlarge-
ment of the spleen. This is a very frequent symptom of long standing and
repeated malaria infection ; other diseases may cause the spleen to enlarge, but
in this Colony such conditions are so few And rare that their influence may be
overlooked. The splenic index, being affected mainly by chronic a nd repeated
infections,. supplies information more particularly as to the habitual incidence of
malaria in the locality.

It will be noted, therefore, that the Parasite and Spleen indices give some-
what different information ; by their comparison we are enabled to date the
local malarial outbreak and to decide whether we are in the presence of recent,
epidemic or acute malaria or of old standing, habitual, endemic or hyperendemio
malaria.

If malaria has only occurred recently, in epidemic form, many ohildren
will be found with parasites in their blood, but their jjgleen, in most cases, will
be only slightly if at all affected. The parasite inallt, therefore, is relatively
'high whilst the spleen index, is low. Conversely if malaria has prevailed in
the district for long years parasites and enlarged spleens will both be prevalent,

. and the spleen and parasite indices will, more or lessf Coincide. These points
-are well shown in diagram No. 1.

138

AQBICTTLTtrBAX JOURNAL 07 BRITISH GUIANA.

[IX, 3.

In the comparative study of spleen rates, in this Colony, it is very import-
ant to give fall consideration to the racial factor. Negroes, though equally
susceptible to malaria as other raoes, tolerate the infection better, and react lea*
frequently and less conspicuously with splenic enlargement. In communities
where Negroes abound the spleen index alone may give misleading results ; it
should always be supplemented by the parasite index. Diagram No. 2 dearly
illustrates this point.

Between 1933 and 1937 we carried out repeated malarial surveys at Blair*
moot and Providence on the Berbice River estuary, and at Bath on the West
coast of Berbice. In 1937-38 we extended this survey to fifteen other estates
from De Klnderen, on the West Coast of Demerara, to Skeldon on the Corentyne
estuary. During the latter survey 5,814 children were examined for enlarge-
ment of the spleen and from 2,389 blood slides were taken for the demonstra-
tion of malaria parasites. Haemoglobin percentage estimations were also taken
from each child, in order to determine the incidence and degree of anaemia.

These surveys have shown malaria to be endemic or even hyperendemic
along the West and East Coasts of Demerara, and on the Demerara and Berbice
river estuaries, with a tendency to become less prevalent on the coast as we
proceed towards the east.

At Bath, on the West Coast of Berbice, locally aoquired malaria is definite-
ly uncommon. In our last survey in 1937, the spleen rate was only 1.3% and
the parasite rate 3.5%. On the Corentyne Coast malaria, under normal climatic
conditions, is even less common.

The last two years (1937 and 1938) have been definitely abnormal as
regards malaria incidence. Between August and November, the disease prevailed
in localities which are usually only mildly malarial ; malaria also became
relatively common on the Corentyne Coast where, as a rule, it is absent.

Our survey, during this period, yielded some interesting figures :

At Albion, with a spleen rate of only 0.1% we found that 19.2% of children
harboured malaria parasites (1937).

At Port Mourant the spleen rate was 0.3% and the parasite rate 13.5%.

At Skeldon 2% and 20.8% respectively.

These remarkable discrepancies between the spleen and parasite rates, as
has already been stated, indicate that malaria is not endemic on the Corentyne
Coast. Its relatively high incidence, in 1937, must be regarded as a purely
epidemic and, therefore, transitory occurrence. We will return to this subject
later when dealing with the seasonal incidence and local epidemiology of the
disease. ^

In the settled areas of the interior, on the Demerara, Berbice, lower
Essequebo, Pomeroon and other tidal rivers, malaria is endemic and, in many

-In the presence of chronic or repealed malaria infection the splenic
negro child is very much leas marked than in the Eaat Indian. ^ w vn e

t rates conditions on an estate on the West Bank, Demerara ; one soleen

there is clear similarity between the parasite rates of the two raceB, the gr p
rate is less than i of that of the East Indians.

In negro communities, therefore, the spleen rate is of relatively little value ; it
should always be supplemented by the parasite rate.

140

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[IX, 3.

localities, hyperendemic. Its occurrence in tbe upper reaches of these rivers
is notorious ; such localities as the Potaro district and Kurupukari, on the upper
Essequebo, have particularly bad reputations. The Rnpununi savannahs,
formerly regarded as healthy, are reported to have suffered severely of late
years.

This brief review confirms our previous statement that in the Colony
malaria is ubiquitous, but its incidence varies within wide limits. Roughly we
may say that this disease is hyperendemic or endemic throughout the permanent-
ly or temporarily settled areas of the interior ; on the estuaries of the great
rivers and on the West and East Coasts of Demerara.

On the front lands of the coast of Western Berbice it is very much less
common ; on the Corentyne Coast proper there is no endemic malaria, but
epidemic outbreaks recur at intervals. On the wide estuary of the Corentyne
malaria of late years, has been very mild, but during the last twelve months a
severe exacerbation has been noted.

What correlation exists, if any, between thin peculiar distribution of Malaria
and that of the three prevailing Anopheline U/teeies '

A. tarsinianila/as is only occasionally found in the forest areas of the
interior, in localities from which the bush has been cleared. This low incidence
is evidently and grossly disproportionate to the very high incidence of malaria
in these districts. On the coast this species is abundant everywhere ; we have
found it particularly prevalent in mildly or non-malarial localities on the
Western Berbice and Corentyne coasts.

A. albitarsis is eminently a savannah mosquito. We have not found it
along the highly malarial tidal and flood rivers of the interior. It abounds
throughout the East and West Coasts of Demerara, in pastures and rice fields ;
it occurs in exceptionally large numbers on the backdams of Western Berbice
estates and on the Abary savannahs. It is very common at Bath where malaria
is only very mildly endemic. So far we have few data concerning this species
on the Corentyne Coast but we had no difficulty in finding it at Skeldon, where
it is very prevalent in the cane cultivation aback. We have also found it in cow
and sheep-sheds at Industry on the Corentyne front lands, some 12 miles East
of New Amsterdam.

In our collection from the savannahs of the Rupuuuni this species accounts
for A of the specimens. The periodic occurrence of mosquitoes in myriads
during and after the rains has always been a well known feature of these
savannahs. Myers established that these mosquitoes were all Anopheles ; but he
failed ^o determine their specific identity. From these and our own findings
w,e would conclude that during the wet season A. albi tarsia is exceptionally
abundant on the Rupununi, and that it was equally abundant a few years back,
when the savannahs were rsgarded as free from indigenous malaria. •

MALARIA nr BRITISH GUIANA.

141

We are, therefore, led to conclude that the geographical distribution of
4. tarsimaculatus and 4. albitarsis in the Colony does not coincide with that
of malaria. Both these species are rare or absent where malaria is at its worst
and conversely they abound habitually where endemic malaria is low or even
absent.

The geographical distribution of A. darlingi on the contrary coincides
rigorously with the local distribution of malaria, moreover the incidence of
malaria is directly proportionate to the incidence of this mosquito.

Where 4. darlingi abounds malaria is hyperendemic ; where it is found
habitually but in smaller numbers or only at certain seasons, malaria is endemic
and seasonal ; where it occurs occasionally endemic malaria is absent but
occasional epidemics follow in its train.

Of the three species of Anopheles we are investigating 4. darlingi is the
only one which is prevalent and wide-spread in the forest areas of the interior.
It is very prevalent on the heavily infected river estuaries, and on the West and
East Coasts of Demerara ; it is, at present, very abundant on the West Bank of
the Corentyne estuary where an epidemic of malaria appeared in August last
year, and still persists.

This Anopheles is represented in our Rupununi collection. At Bath, in
Western Berbice, where malaria is very mild, this species occurs but is rare.
Of 669 Anopheles captured on this estate in 2 years, only 56 belong to this
species. (,)

On the Corentyne coast 4. darlingi is usually absent, but we found it
present in small numbers at Port Mourant in October 1937, when a small
epidemic outbreak was active. An epidemic is at present active at Albion ; we
visited this estate on the 5th of September, and found 4. darlingi abundant in
the houses.

Even on individual sugar estates, studying the incidence of 4. darlingi in
different yards and houses, in parallel with the malarial parasite and spleen rates,
one is inevitably led to conclude that not only the geographical, but also the
topographical distribution of this particular Anopheline species and that of
malaria strictly coincide.

( 1 1 In August this year, sinoo the present section was written, an epidemic outbreak of
Malaria of some seventy has occurred at Bath. The spleen rate has risen from 1.5% in 1937 to
20% and tbe parapite rate from h.5% to 69%.

A. darlingi has appeared in very large numbers and on the 19tb of September, in one hour
we captured no less man 460 specimens in the bouses; 140 were caught in a single room of a
range situated in dose proximity of the cultivation.

Hot a single A tartimacvlatut or A. albitarsis was found in the houses, in spite of the fact
that the larvae of both these species were enormously abundant in all the surrounding irriga-
tion eanala, outnumbering those of A. darlingi many times over.

The causes of these unsual malarial outbreaks will le dealt with later under tie Leadicg
Epidemiology.

A. B C

3 :-~The correlation of the distribution of malaria and that of A. darlingi ia not only
geographical, but also topographical. This diagram refers to three separate villages
belonging to the same East Coast estate, all situated within a radius of approxi-
mately 1 mile. The vertical columns indicate the spleen rate, and the curve the
„ number of Anopheles captured by searching the houses for 2 hours in each locality*

MALARIA Iff BRITISH GUIANA, 143

One o£ the estates, on the East Coast of Demerara, has its population distri-
buted in 3 yards. In these the incidence of malaria varies within wide limits.
On the 11th and 12th of August of this year, we carried out mosquito captures
in the houses of these different yards, roughly the same time being devoted to
each one.

In the following Table we correlate the number of A . ddrlinyi captured to
the spleen rate amongst the children in each yard :

Table I.

Yard :

Spleen

Rate :

A. darlingi
Captured :

Yard A

73.2

430

Yard B

49.4

172

Yard C

6.5

1 11

II. Domesticity of the Local Anophelines.

The term 44 domestic ” does not apply sensn strirto , to any of the local
species of Anopheles, as none of these is in the habit of breeding in water
collections or containers, pertaining to houses or their immediate surroundings
(rain water tanks, vats and barrels, sagging gutters, discarded tins, etc.) In
systematic inspections carried out during the last 15 years, we have never
found anopheline larvae in such waters.

By “ domesticity ” we here mean to signify simply the tendency of these
mosquitoes to enter houses. This is a point of very great practical importance,
as it is an established fact that malaria is rarely contracted in the open.

In the following Table we give the relative incidence of A . darlingi,
A. tarsunaculatu8 and A. albitarsis in a series of 15,035 Anopheles captured in
houses on the Guiana Coast during the last 4 years.

Table II.

Anopheles

Captured.

Relativ

a Incidence

Per 100

Locality.

A. darlingi .

A . tarsimu-
mlatus .

A. albitarsis

Tuschen

503

99.8

0.2

0.-

De Einderen

638

99.4

0.5

0.1

Uitvlugt

452

99.4

0.6

Wales

815

100.-

0 .-

Ogle

120

99.2

0.-

0.8

Vryheid’s Lust

366

98.6

0.3

1.1

La Bonne Intention

788

99.8

• 0.-

0.2

Blairmont

8,718

84.-

3.4

12.6

Providence

1,289

97.9

1.9

0.2

Skeldon

1.346

100.-

0.-

ToTE

15,035

99.1

0.2

0.7

144 AGRICULTURAL JOURNAL 07 BRITISH QUIAKA. f DC, 8*

It will 1m noted that the domestioity of A. tarsimaculatns is consistently
negligible throughout the coast ; only at Blairmoat A. albitarm wag o&ptured
with a certain frequency; this is doe to the fact that the greater part of our captures,
on this estate, were conducted in the village of Rampoor, which is situated 4
miles inland, on the edge of the Abary cattle savannahs where this mosquito is
often extremely abundant. In this locality we found that whereas A. darlingi
was constantly present in the houses, in more or less consistent numbers, accord-
ing to season, A. albitarm would be found fitfully, sometimes being absent,
nsaally representing only 3 to 5 per oent., but occasionally as much as 15 to 25
per cent, of the Anophelines captured. In the open, in this locality A. albitarm
was always and by far the most abundant species from May to November.

In this same locality we also noted that the great majority of A. albitarm
captured in houses showed no evidenoe of having recently fed. This is well
shown in the accompanying photographs.

Table 1 demonstrates that A. darlingi is very definitely attracted to houses ;
this is evidently, not the case for either A. tarsimaculatus or A. atbitarsis, The
two latter species not rarely may be caught in estate hospitals or staff houses,
where they are attraoted, like myriads of other night flyers, by the bright
electric lighting.

It might be argned that this different incidence in houses may simply be
an expression of the different general incidence of the three species in the locali-
ties we have studied. This is certainly not the case, as A. albitarsis and
A. tarsimaculatns could always be found in numbers, when searched for in
their habitual haunts ; moreover, the collection of larvae in surface waters (which
was always carried out systematically and in parallel with the capture of adults)
showed the larvae of these species to be constantly equally numerous, and often
■very much more so than those of A. darlingi.

III. Biting Habits.

.4. darlingi is strictly a night flyer, becoming active soon after dusk. It
undoubtedly bites man selectively.

We have investigated the incidence of the various Anopheles in
shelters such as stables, cow and sheep pens. In many instances we have
carried out captures on horses tethered in the open in close proximity to houses
in which A darlingi was present in large numbers at the time.

Fig. 4 : — Ilmdom sample of -1. * hthnf/t ciptured in houses in the \ ill u;e of R unpoor (Blairmont) which is situated m
land on the cdiye of the Aharv Sivamuh. With very few exceptions all aie gomed with blood.

A t Jarlinji enters hou^c^ in large numbers and feeds on man select i\ elv .

Plate ii,

Fig. 5 : — Random sample of A alfutams ouirht in houses in the same village. AYith \er> few exceptions none appear
to have fed recently, A albttcu ws enteis houses ictidentdlj and feeds seiectiv elj on animals, cattle, horses
and sheep in particular, both in shelters and in the open.

MALARIA IN B&mgB GUIANA.

145

The following Table summarizes oar findings :

Table II.

Locality.

Anopheles

Captured

Relative Incidence Per 100

A. darlingi

A. tarsima-
culatus.

A . albitast8

] . .

De Kinderen

11.9

85.1

: ’

Uitvlugt

98.5

1.5

Wales

93-

Blairmont ")

Bath }

1,883

2.3

52.5

45.2

Providence )

Skeldon !

| 135

5.2

91.8

Industry

(Corentyne Coast)

533

99.1

! 0.9

Total.

2,61)'*

2.2

, 39.9

37.9

A. tarsimaculatua and, more especially, .1 albitarsis when disturbed from
their resting places in close proximity to their breeding sites, will frequently
attack by day even in full sunlight.

On the back dam of the Western Berbice estates and on the Abary
savannahs *4. albitarsis may be very troublesome even by day.

All our observations, in conclusion, tend to show that .4. darlingi is
definitely anthropophilous in its feeding habits, i.e„ it feeds on man selectively and,
to this purpose, it enters and rests in houses in large numbers and, presumably,
if conditions are favourable, it may fly considerable distances in search of its
favourite meal.

A. tarsimaculatua and .4. albitarsis are, on the contrary, strictly ioo/diilous,

they feed selectively on animals ; for this reason their favourite haunts are
animal shelters of various description.

IV. Conclusions.

Reviewing the data which have been presented in this and the previous
section, we are led to the following conclusions :

(1) There are three species of Anopheles, in this Colony, which by their
number and wide distribution must be regarded as possible vectors of malaria.
These species are A. tarsimaculatua, A. albitarsis, and .4. darlingi. The
existenoe of the latter two species in this Colony was not previously known,
both having been confused under the erroneous denomination of .4. argyri *
tarsia, a species which, though valid, we have failed to find in British Guiana.

146

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[IX, 3.

(2) An investigation on the local geographical and topographical
distribution of these three species of Anopheles reveals that the distribution and
incidence of malaria is strictly parallel to the distribution and incidence of A.
darlingi, a species which enters houses and feeds on man selectively. A.
tarsi maculatw and A. alhitarsis abound in localities which are habitually free
from endemic malaria ; when malarial epidemics occur we have always been
able to demonstrate the presence of A. darlingi ; the severity of such epidemics
is directly proportionate to the incidence of this mosquito.

(3) A. tarsi maculatw and A. alhitarsis, which abound on the pastures,
sugar and rice plantations and on the savannahs of the Coast and far interior,
bite animals selectively and cattle in particular. They enter stables and cow-
sheds in search of food; human habitations only accidentally. A. alhitarsis
even when caught in houses rarely shows evidence of having fed on the
occupants. The absence of endemic malaria in localities where only thoBe two
species abound, as at Bath and on the Corentyne Coast, is easily explained;
these species, by feeding selectively on animals, are not liable to acquire and
thereby, subsequently, transmit malarial infection.

(4) We have ourselves been able, without difficulty, to infect in the
laboratory locally bred A . tarsi maculatw and A. alhitarsis with local strains of
malaria parasites, ( P . vivax ), but we are of opinion that the importance of both
these species is negligible from a malariological standpoint : in order to be an
effective carrier a mosquito must bite not once but repeatedly : it must feed, in
the first place, on a human subject harbouring malaria parasites in a suitable
phase; after an incubation period of at least 10 days the mosquito becomes
infective, but, evidently, in order to transmit malaria again to one or more
persons it must again feed on man, on one or more occasions. The figures and
observations we have recorded which, we believe, are based on adequate material,
were collected over an adequate field and for an adequate period, evidently
show that both for A , tarsimaculatus and A. alhitarsis , the likelihood of such
repeated attacks on man by an individual mosquito is sufficiently remote or, at
least, unusual to lose all practical importance.

(5). We, therefore, ultimately conclude that A, darlingi is the sole
malarial vector of practical importance in this Colony.

(To he Continued).

COCONUT WILT IN ESSKQUIBO AND POMEKOON

DISTRICTS.

D. W. DPTIIIE, ph. D., F.I.C.

( '/trill in/.

I. General.

Wilt disease of coconuts has existed for many years in the Caribbean area,
and it has been the subject of several investigations. Follett-Smith (Ann. Rep.
Choni. Div. 11)30 p. 107) made one of the earlier investigations of the disease,
but he found the evidence so conflicting that he made no definite statement,
apart from noting that there was a higher content of available phosphate in the
soil of healthy ureas as compared with affected areas. Recently, Bain published
the results of a long investigation of Trinidad Wilt (Bull. Dept, of Agric.
Trinidad, 1037) and explained the disease as being duo to the curtailment of
root growth by a high water table at certain times of the year, followed by dry
soiisons which the restricted root system could not withstand. This explained
the puzzling fact that trees grow normally for several years, as even a
relatively small root system is sufficient to keep young trees in good health,
but the strain of bearing is usually the critical [mint.

II. Coconut Wilt on the Kssbouibo Coast.

b'irhl ObmTatiam.

Trees 15-25 years old are affected, and the symptoms are almost
identical with those in Trinidad — the lower leaves show a characteristic
bronzing at the tips, the nuts are shed, the remaining leaves wither, and finally
the whole crown falls. A noteworthy feature is that, generally speaking, the
disease moves in the direction of the prevailing wind.

The disease occurs both on clay and on sand, but the sandy areas are so
small in proportion that they were omitted from the present investigation, as
only limited time was available for field work.

Soil Sump! i ni/.

Top soil andBubsoil samples (0-12 inches and 12-21 inches) were taken in
three areas on Pin. Laud of Plenty, vizi —

(a) A healthy bed in a heavy clay area (Field No.- 1 Chinee Land)

(b) An adjacent bed in the same field, in which the trees were all affected.

(c) A field some distance away (Three Friends South, Cross Dam Field)
of similar flail typo, in which the trees had completely wilted about two years

14 $ AGRICULTURAL JOURNAL OP ShifISR GtJlANA. flX, 3 .

before, since when the land had been covered with bush. It had recently been
cleared for planting ground provisions.

Soil Analyses.

The complete analytical data are given in Table I.

Table I.

Analyses op Soil Samples from Pln. Land op Plenty, Esbequiro Coast.

Field No, 1 Chinee
Land Healthy Bed

Field No. 1 Chinee
Land Vfili Area

1 3 Friends Cross Dam
'Field Wilted, then in

1 bush 2 years.

E 430

E 431

E 428

E 429

> E 432

E 433

Depth

0—1 ft

1—2 ft.

0—1 ft.

1-2 ft.

^ 0-1 ft.

1-2 ft.

Normal Reaction (pH) |

Exchange Reaction (pH) i

5.0

4.7

4.9

4,8

3,9

4.2

3.8

4.3

3.7

% sand

3.3

3.8

0.4

6,7

Index of Texture

38 r

1 .13

% Soluble Salts
y o Organic Matter %

0.009

0.283

0,158

0.433

0.012

1 0 050

153

1.30

2.98

2,40

1.97

1 43

°L Nitrogen

0.158

0.105

0.172

0 112

0.147

' 0.119

Carbon/Nitrogen ratio

5.0

7.2

10.1

12 9

1 8.0

1 0,9

Lime Rqt. Tons/acre 6"

3 7

8.3

i 7.4

Avail P, 0, p.p.m. Tiuog

1 ml

nil

> nil

Exchange ,

(CaO !

333

i 2.35

3.05

3 44

2.18

! 2 02

& Water Sol, j

1 MgO

5,30

I 1105

8.05

12 05

4.51

! 7 72

Bases j

|K,o

0.14 1

i 0 25

0 21

0.18

0.29

0.09

Mg cqvs/100 gms

lNa,0 j

: 1,80

! 5.38 j

2.38 |

4.02

0.37

0.5O

This soil may be described as an acid clay, markedly deficient in available
potash and phosphate, but with adequate nitrogen and organic matter. It should
be noted, however, that coconuts normally grow on poor soils, so it cannot be
argued that potash and phosphate are the limiting factors. The significant
figures are those for per cent, soluble salts and per cent, exchangeable magnesia
and soda. They indicate that the Chinee Land field soil is suffering from lack
of aeration and drainage, since there is an accumulation of saline substances in
the subsoil. But this is not due to waterlogging, as the soil was quite dry at the
time of sampling, even though there was standing water in the drains between
the beds. Some attention was therefore focussed on the water relationships
of this soil.

Soil Moisture.

The rainfall from 1st January to the date of sampling (24th March) was
abnormally high : 11.6 inches fell in January, 6.25 inches in February and

13.11 Inches from 1st to 24th March. Most of the drains contained water, but
the soil in the centre of the beds was by no means sodden. An attempt was
made to find the water table, but this oould not be reached with a 2*— ft. auger

COCONUT WILT Itf ESSBQUlBO AND POllKROOJf DisTRIOTP. 149

even by boring less than six inches away from a drain containing water. Thus
the peroolation of both rain and drainage water is extremely small, and soil
samples from the healthy bed in Chinee Land Field were taken in sealed tins
(0-6", 6-12", 12-18" 18-24") for moisture determinations. Table II gives the
detailed results, along with approximate figures for the Wilting Point of the
soil, i.e., that moisture content at which the plant is unable to overcome the
attraction of the soil for water. These figures show that the soil had a gross
moisture content of about 25 per cent., the danger point being about 13 per cent.

Table II.

Soil Moisture Relations of Healthy Coconut Bed at

Land of Plenty.

Depth

' 0-6"

6-12"

12—18" |

18—24'

Gross moisture %

1 23.0

24.0

| 26.0 ;

27.6

“ Sticky Point” moisture % (P)

32.8

37.8

. 35.2 1

32.7

Sand %

3.3

2.3 !

2.3

Wilting Point moisture %
[0.37 (P - 1/5 sand)]

12.0

13.8

13.0 t

12.0

Thus in spite of the heavy rainfall of the previous three weeks, the soil had
only 12 per cent, available moisture, and in dry spells it would probably
approach the danger point, which may be even higher than 13 per cent, on
account of the comparatively high salt content of the soil (i.e., magnesia and
soda).

Hoot Distribution.

Further observations confirmed the suggestion that movement of water in
the compact clay might be the key factor in the disease. Trenches were dug
round two trees, one which had died about two years before, and one which
was Just beginning to wilt, and their root systems were examined. Approxi*
mately 50 per cent, of the roots were found in the top 6 inches, about 25 per
cent, in the second 6 inches, and the remainder were sparsely distributed down to
four feet. The roots tapered off rapidly from the base of the tree, and it was
evident that they were not finding it easy to penetrate the stiff clay. A distinct
colour change in the soil was noted at 15 — 18 inches from the surface, being the
depth to which cultivation had been reached when the land was tinder
eugar-cano. ,

Cause of the disease .

The roots of forest trees and bush penetrate into the soil as far as six feet
even in a heavy clay, and thus aeration and drainage are maintained Jar below
the surface. If the trees are cut down and another tree crop, such as coconuts*
is planted, tie young trees will have an opportunity of sending their roots

i56

AGRICULTURAL JOUftttAt Of BRITISH GUlAtJA, '

[IX, 3.

equally far into the soil. Changing from bush to coconuts does not cause any
great change in the soil structure, and even on poor soils where this change
has taken place, the coconuts have given good yields over many years.

The widespread cultivation of sugar-cane in this Colony led to large areas
being changed from bush to sugar-cane — a shallow-rooted grass crop which
exploits the top 18 inches of the soil and leaves the lower layer's free from roots .
The soil ecology was drastically altered, since the topsoil was intensively
cultivated and the lower layers were allowed to become compact and “ lifeless,”
On heavy clay lands the natural drainage was thus impeded and an elaborate
drainage system had to be constructed in order to get rid of excess water as
rapidly as possible.

When economic conditions led to the abandoment of many sugar estates,
coconuts were planted on some of the old cane beds, and the young trees found
themselves in a well-drained highly organic topsoil, which favoured their
rapid growth. As the roots passed down from the cultivated layer, they
found a saline, compact clay with little oxygen f and a limited water
supply, and thus the greatest root development took place in the
surface soil. A jnass of roots developed near the surface which further hindered
the penetration of water, and the added strain of bearing fruit left the trees
undernourished and sickly.

The coconut tree is sufficiently hardy to withstand lack of soil nutrients,
but a good water supply is essential, and in dry periods the soil on the windward
side of a field would rapidly dry out and approach the “ wilting point”. If a
few trees died, their shade would be removed, lack ot* moisture would affect the
neighbouring trees, and wilt would gradually move in the direction of the pre-
vailing wind.

It is significant that fields which appear to be waterlogged, overgrown with
bush, and generally ‘ 4 neglected’*, do not show signs of wilt, and the natural
reaction of the planter is to consider these good fields and to underlmsh and
improve the drainage whenever the price of copra rises. By doing this he is
aiding the rapid run-off of water, increasing the evaporation from the surface
of the soil and possibly causing wilt to appear,

To sum up, wilt disease of coconuts on the heavy clay soils of the Essequibo
Coast is probably caused by planting coconuts on old cane beds, where the sub-
soil is too compact and saline to allow easy root penetration, with the result
that the topsoil becomes a mass of roots, and percolation of water is greatly
hindered. The trees are thus, living on the verge of drought, and ** physiologi-
cal drought” will also play an important part, owing to the high content of
magnetfa and soda even in the topsoil. When evaporation from the soil surface
is increased by “ clean-cultivation” or by the death of a few trees, wilt appears
and spreads slowly in the direction of the prevailing wind.

COCONUT WILT IN EB8EQUIBO AND BOliEROON DISTRICTS.

151

Cure and Prevention .

It is clear that soil aeration and water penetration mnst be improved, but
the thick roots of the coconut tree render inter-cultivation very difficult. It
might be feasible to use a harrow, gradually going deeper and forcing the roots
down, but this would not improve the subsoil, and it would be difficult to im-
prove the condition of trees which are threatened with wilt. Planting
windbreaks, encouragement of deep-rooted woody ground cover, and even
flooding for short periods might ameliorate the condition to some extent, but the
subsoil conditions would probably remain the same. Mr. S. H. Seymour of
Pin. Affiance has suggested the use of dynamite to shatter the subsoil when it is
dry, and this is wortli trying, as it may even be economic on a fairly large scale.
Oil geologists have recently used dynamite in conjunction with seismographs,
in order to interpret the deep strata, and thus the effect might be more wide-
spread than is generally supposed.

With regard lo fields which arc to be replanted with coconuts the procedure
is straightforward. Flood-fallowing for long periods — over twelve months—
would probald y do much to improve the subsoil conditions, but the safest method
would be to leave the land in bush for a few years before replanting. Table I
gives the soil data for a field (Three Friends South, Cross Dam Field) in which
the coconut trees had all wilted and the area had been left in bush for about 2
years. There is a marked difference in the subsoil from that of the Chinee
Land Field, as the saline components had been partly removed. In this field the
surface soil was much more friable than in the Chinee Land Field, and it is
probable that a longer period in bush would improve it even more.

These arguments and considerations were the result of discussions in the
field with the Deputy Director of Agriculture, the Agricultural {Superintendent,
Essoquibo, Mr. S. II. Seymour (Pin. Affiance) and Mr. E. Taylor (Pin. Laud
of Plenty) and thanks are due to them for valuable information and suggestions.
The soil analyses were carried out by the Assistant Chemist, Mr. C. L. C.
Bourne.

III. Coconut Wilt on the Pomeroon River.

Several small areas on the banks of the Pomeroon River have been planted
In coconuts, on soil which varies from deep pegasse to pegassy clay. The trees
grow particularly well at first, come into bearing very early, sometimes when only
three years old, but they wilt at about 10 years. An area which lias been
replanted after wilting will show equally good promise, but it may show signs of
wilt after 7 or 8 years, and repeated planting appears to shorten the life of the
trees to as little as 5 years. Generally speaking trees on the dams grow well,
even on clay, and they may live for 20 to 30 years without showing signs of wilt.

Field observations showed that the conditions fitted Bain’s explanation of
Wilt in Trinidad. In wet seasons the water table at high tide is 18 to 24 inches
below the Surface, the soil is well aerated and conditions are admirable for the

152 AGRICULTURAL JOtffttfAL OP BRITISH GttlAifA. [IX, 1

growth of trees while they are young. Root growth is limited by the high
water table, and thus the trees die when their root systems develop beyond a
point which depends on their height above the river. Cultivation and aeration
of pegasse causes it to shrink rapidly, and thus the water table is nearer the sur-
face when the field is replanted after wilting.

Dwarf Coconuts might survive longer under these conditions, but the most
satisfactory remedy would be to plant coconuts only on land which is at least
6 feot above the water-level of the river at high tide, as proved by test borings.

A GRADE DAIRY HERD.

H. A. FRASER, B.V.Sc.,

Government Veterinary Surgeon ( Ag,).

One of the principal objects for the establishment of this herd was to
demonstrate that a good grade dairy herd could be made an economic success
in British Ouiana and also to provide reliable data on the various problems
arising.

Intensive methods of production have been employed, as land carrying a
dairy herd bears a high rental owing to the fact that it needs to be reasonably
well drained and to have a reliable water supply throughout the dry season
for the pasture.

The herd was started in 1929 with two cows, and by 1932 nine head were
added. In 1933 it was put on a commercial basis, and from then to 1934, 11
head were purchased. Since then, no further additions to the herd by purchase
have been made, as improvement was very disappointing and uniformity difficult
to attain through animals whose ancestry was not known. In dairy herd improve-
ment the only sound and economic breeding policy is to breed the best to the
best, therefore only purebred bulls were used on the best cows, all low
producing animals were weeded out, and the female calves raised for replace-
ment. Thus improved production and uniformity were gradually attained.

The following Table shows the number and classification of the herd at
half year ending June 30, 1938: —

Table I.

Cows

| Heifers

1 Bulls

Total

Parebred Guernseys

—

„ Holsteins

—

1st grade Holsteins

—

2nd „ „

—

3rd M «»

4-tli h ««

—

3 48

It will be seen from the foregoing table that all the Creole milch cows that
had been originally purchased were disposed of, and the present herd are all of
improved breeding.

The first cross heifers in milk that were not up to standard were sold at a
good price, and there has been a steady demand by buyers for grade milch cows
or heifers in calf. Unfortunately, the same cannot be said of grade bull calves,
— cattle-owners seem disinclined to buy good grade bulls to improve their herd,
although there has been an improvement in the sales of these this year.

Table No. II, is given from a productive point of view and shows the
number of days cows have been milked and the quantity of milk obtained
during each 'lactation.

154

AGRICULTURAL JOURNAL OP BRITISH GUIANA,

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[IX, 3.

A GRADE DAIRY HERD.

155

The highest daily yield of 41 pints milk was obtained this year from
“Elsie,” a purebred Holstein cow born in the Colony. In 31 days she
produced 1,502 lb. milk and seems likely to complete her lactation with 12,000
lb. for the year. “ Bessy 2nd,” a second cross Holstein cow freshened with 36
pints milk per day and a total yield of 8,834 lb. milk in 357 days. “ Maokie,’’
another seoond cross Holstein cow, gave 34 pints milk per day and a total of
10,063 lb. in 415 days. There are also other grade cows that have given 36
pints daily, but have not yet completed their lactation. These yields are
especially gratifying as the animals are under the nsnal routine of feeding and
management.

MILK PRODUCTION.

The production of milk has continued to increase.
Table III shows the annual production.

Table III.

1033

1034

1035
103(5

1037

1038 (8 months)

12,028 pints
28,862 „
35,083 „
50,980
50,005 „
50,000 „

The work of grading up the herd with purebred Holstein bulls has been
carried on ; the young animals of the fourth cross are showing the characteristics
of the purebred Holstein.

Tabic IV shows the pedigree of Bessy 4th, a fourth cross Holstein heifer

Table IV.

Sire

(Demerara Kerk

JJosxj 4 tli

[Dam

Sire __

Sir Rochani
Kerk

[ Sire
i Pontiac
I Jew el de Kol.

Bossy 3rd.

Dam

Bessy 2nd

Dam
Bess) 1st

Sire

Texas Wonder
Dam

Creole Cow.

There are only two crosses more to attain the top grade which is considered
purebred, btft is not eligiblo for registration in the herd book of the breed.

ISfl * AGRICULTURAL JOURS AX OP BBITISS GUIANA, [IX, 3,

Table V dearly shows how the grade blood disappears!—

Table V.

Generations.

Sire’s %
of purity.

Dam’s %
of purity.

Offspring's %
of purity.

Percentage of
unimproved blood.

1st cross

2nd „

3rd „

87.5

12.5

4th „

87.5

93.75

6.25

5th „

93.75

96.87

3.12

6th „

96.87

98.44

1.56

Grading up is the cheapest and most economical method of herd improve*
ment. The following table showing production and net income of Holstein
grades and Creoles nnder similar conditions serves to indicate the important
part that a purebred sire plays in improving the herd.

Table VI.

Breed

Lactation

Period

Total

Yield

Milk fed
to calf

Milk sold

Net

Income

lb.

Creole

4th

3,302

1,558

1,774

19.88

5th

2,738

1,556

1,172

5.19

6th

3,543

1,734

1,809

25.80

4th

2,738

1,650

1.088

i 4.49

»»

5th

2,330

1,526

864

— 5.52 Loss

6th

2,807

1,614

1,193

i 3.44

Holstein

4th

6,014

1,806

4,208

108.98

1st Cross ,

5th

6,222

1,798

1,424

108.32

,, J

6th

6,470

1,780

4,690

122 83

Holstein 1

1st

5,260

1,770

3,490

J 81.47

2nd Cross 1

2nd

9,712

1,770

6,142

1 164.35

The above shows that the Creole cow even when carefully selected has no
place in economical dairying. The lactation period is too short, only abont
eight months, while the Holstein grade will milk for a year or more. The
oomgarison was made over a period of 3 years and all the animals came into
lactation within a few weeks of each other, so that seasonal conditions were
practically the same for each trial, AU the Creole animals were disposed of
after this experiment,

Plate iii.

Fig. I : — ‘‘Orchard Leigh Heilborn Mercedes/ 1 A pureberd Holstein-Fricsian Bull
owned by the Department of Agriculture.

Fig, 2:—' “Candies Carbine. 11 A purebred Guernsey Bull owned by the Department
of Agriculture.

Plate iv.

Fig. 3 A Grade Holstein-Creolc. Herd.

Fig. 4:— Grade Holstein- Creole Calves, 10—12 months old, reared on a commercial qalf meal feed.

A GUAM DAIRY HERD.

157

Calves are allowed to suckle their dam 24-36 hoars after birth to obtain
the colostrum. They are then removed from their dam and fed milk from a
pail until weaned at 6 months of age. For the first two weeks of life, the yonng
calf is fed 6 pints of milk daily divided into three feeds. Thereafter the milk is
increased to $ pints daily, and is given in two feedings. After the third week,
concentrates and grass are fed in addition to milk, the concentrates being in-
creased gradually every month so that by the 5th month the calf is getting 4—5
lb. daily and all the grass it will eat. Glean drinking water is available at all
times ; this is an important detail that should not be neglected ; calves fed under
this method are thrifty and well grown when weaned. The cost of feeding
whole milk from birth to weaning is however, rather high, averaging about #70
as the following table shows : —

Table VII.

Months.

Weights.

Total Feeds.

Daily

Gam.

Cost per month.

1st month

lb.

birth

weight

110

lb.

Milk 270
Grain 12

lb.

147

10A6

2nd month

165

Milk 252
Grain 15

1.89

i 9.88

3rd month

210

Milk 304
Gram 78

145

12.56

1th month

240

Milk 300
Grain 90

100

13.05

5th month

310

Milk 310
Grain 121

.• 2.26

14.00

6th month

310

Milk 192
Giain 159

1.00

*10 00

#69.95

Calves were reared somewhat cheaper this year than formerly, by feeding »
limited amount of whole milk and then substituting gradually an imported calf
meal. Unfortunately the calf meal was finished during the 5th month so that
the experiment could not be carried out for the full period, as the meal could
not be obtained locally. The growth and condition of the calves were quite
good and the ayerage cost was 138 per calf. This large saving in the cost of
rearing calves should be of great help to local dairymep,

158

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[IX, 3.

After oalves were weaned they were pnt'on to good pasture, and all grain
feeding discontinued. It was noticed that up to about the sixteenth month of
age growth had practically oeased but condition was maintained. After the
sixteenth month, however, the rate of growth increased rapidly and good gains
were made. Calves fed grain up to about the 14th to 16th month were pat on
good pasture ; no appreciable setback occurred in the rate of growth and gains
were good.

Why growth should almost cease from weaning to the sixteenth month
seems to be explained by the fact that the digestive system of the weanling is
not able to assimilate the nutrients in grass necessary for growth as the digestive
system of the older animal is abie to do.

In order to obtain accnrato information as to normal growth, monthly
weights and measurements for height were made on 12 calves as Table VIII
shows.

Table VIII.

Age in Months

Height at Withers, |

Inches. ,

Weight

lb.

Birth

28 1

29.5 i

110

31.5 !

142

3 1

32.7

184

210

260

296

38.2

320

39.5

356

40.5

394

41.5

421

442

473

It is intended to keep on with this experiment until the animals are 24
months old, should weighing facilities be available.

The following is the weight of two animals that were put on pasture at 8
months of age and have since received no grain.

Height Weight

f4th month 41.5 389

15th month 42.2 396

Many -of the dairymen of this colony do not feed their calves adequately.
The allowance of milk is too small for growth and after the weaning period very
little grain is fed. Therefore many of these animals are not big enough to bp

A GRADE DAIRT HERD,

159

brad until they are over 3 years, and do not come into production until they are
4 years and over.

Hjeifers that are veil grown are bred at 18 to 20 months old. In order to
maintain growth and development it is neoessary to feed concentrates during the
gestation period.

. Feeding Stuffs.

The feeding of grain is one of the most expensive items of expenditure. The
continned rise in the price of local foodstuffs and the uncertainty of obtaining
regular supplies were two of the most disturbing factors throughout the year,
thereby increasing the cost of production. The margin between the cost of
production and the selling price of milk is so small that when foodstuff prices
increase above the small seasonal fluctuation, it tends to disappear very quickly
and a loss occurs.

The value of a feed is largely determined by its composition and palatability.
If deficient rations are fed the milk supply will drop, consequently some
dairymen do not get as good yields of milk because of poor feeding.

Rice bran, broken rice and coconut meal are the principal concentrates used,
but require a high protein feed such as linseed meal, soya bean meal or cotton-
seed meal to balance the ration.

Molasses is a good feed as it helps to make the food more palatable and
reduces the cost of the ration.

The following ration has been used with good results.

Rice bran

100 lb.

Coconut meal

50 „

Soya bean meal

20 „

Linseed meal .

10 „

Molasses

20 „

Bone meal

4 „

Salt

2 ,.

•*

e above ration fed

to a cow in milk is

gallon of milk produced.

Bone meal has always been included in the ration as the grasses are
somewhat low in mineral oontent, chiefly lime and phosphorous.

Pasture. (26 acres).

This has been the second year of pasture improvement and it serves to
demonstrate the value of rotational grazing on improved grasslands.

When the pasture was first leased it was of a very poor type consisting
chiefly of a tough wiry sedge, black sage and a few varieties of grass. It had to
be completely fenced and was subdivided into paddocks. The sedge and sage
weye cut and burnt and part of the area was ploughed and planted wit|i far^-

160

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[IX, 3.

grass, Indigofera and Demerara Primrose. Only one paddock was manured with
140 cartloads of barnyard manure as the rainy season commenced and stopped the
work. When the pasture was ready for grazing the cattle were turned on and
allowed to graze the paddooks in rotation as Table IX shows.

Table IX.

Paddocks

Head cattle.

Grazing days continuously

No. 1

From Feb. 19 to Apr. 18 — 60 days

„ June 7 to Aug. C — 60 „

No. 2

From Aug. 24 to Sep. 13 — 21 days

„ Dec. 1 to Dec. 24 — 24 ,,

No. 3

From Apr. 19 to June 10 — 21 days

„ Sep. 14 to Oct. 31—48 „

No. 4

From Aug. 7 to Aug. 19—13 days

„ Nov. 1 to Nov. 13 — 13 „

The animals were in good condition and did well on pasture but were not
grain fed as they were dry cows and young heifers.

Water was taken in during the dry weather to irrigate the graSB and keep it
growing ; so that 2,040 lb. grass was cut and cured as hay and fed when grass
was scarce.

The response of the pasture to management is manifested in the marked
increase in the variety of grasses and in indigenous legumeB thug increasing its
nutritive value and its carrying capacity.

To improve pasture one must be asiured of reasonable drainage and a
water supply for the dry months. These two essential requisites indicate that
such land must bear a fairly high rental and thus only improved stock of high
production could pay for its improvement. If dairying is to expand and
become an industry these facts must bo considered and the general principles
ot live stook management be applied.

Diseases.

The general health of the herd has been quite good.

Tuberculosis.

The intradermal Tuberculin test was done for the detection of tuberculosis,
but no animals reacted to the test thus indicating that the herd is free from
infection. Yearly tests will be made in future as a routine measure.

Mastitis

There was one very acute case that resulted in the loss of one of the
quarters of the udder. There were three other mild cases occurring soon after

A Grade dairy herd.

161

parturition, of cows with large bags bat these yielded readily to treatment. The
faot, however, should not be forgotten that the higher the herd is graded op to
heavier producing cows the greater will be the tendency to the occurrence of
Mastitis. Cows most be milked with clean and dry hands, the udder kept clean
and the animal well bedded so as to control as much as possible the external
factors that contribute to diseases of the udder.

Breeding irregularities.

There was a marked improvement in getting the cows back in calf due in
a large measure to having a stud bull on the farm instead of having to take the
oows to the Government Stock Farm to be bred.

Sporadic abortion .

In the latter months of 1935 five cases of abortion occurred within a period
of 2 months, and with cows in varying stages of gestation, at the 7th, 5th, 4th
and 3rd months.

This increasing number of abortions occasioned a great deal of anxiety as
it was feared that the bacilli of infectious abortion might have been introduced
into the herd through a recent purchase of a purebred Holstein cow from a herd
that had some breeding troubles.

The Agglutination tabe test for infectious abortion was made. The litres
used were a 1 : 25, 1 : 50 and 1 : 100 dilution. Known positive and negative
sera were used as controls.

After 48 hours incubation at 37.5 degrees Centigrade the tubes under test
did not show any agglutination thus indicating that the animals were free from
infectious abortion. The positive antigen control tube showed complete
agglutination in 1 : 100 dilution.

Strict hygienic measures were carried out'and all aborting cows isolated
from the herd and treated. They were subsequently rebred and have calved
regularly without any further trouble, and no further cases have ’occurred in
the herd.

Breeding troubles* if neglected, increase every year in a herd and cause a
reduction in milk production and an increase in oost of production.

There is* however* a fairly high percentage of sterility cases among the
milking herds on the coastlands and some work would need to be done to
determine the causative factors and its prevention.

Table % shows the percentages of expenditure under their respective
headings.

162 1

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

£lX,l

Tablb X.

Year

Wages

Feed

Pasture

Sundry

Expenses

Buildings

Total

per cent.

1934

42.78

41.18

4.24

11.80

100

1935

40.41

48.89

—

7.49

3.21

100

1936

39.90

39.03

8.93

12.14

—

100

1937

34.83

40.30

7.86

11.53

5.48

100

It will be seen that in 1937 the benefits derived from the pasture show a
redaction of the feed and wages bills, the two items of heaviest expenditure.

As the rainfall has an important bearing on dairying by keeping the grass
growing over a longer or shorter period, daily records were kept for 1937. The
rainfall for the year was 82.24 inches. The firBt 19 days of Janaary 10.26
inches of rain fell and thereafter a short dry season occurred to April 18, with
only 2.91 inches which caused a scarcity of grass. The mid-year rainy season
commenced on April 19, to Angnst 23, with a rainfall of 52.14 inches. Daring
the wet period grass was abundant. Daring the second dry period Aagast 24,
to December 18, 8.07 inches of rain fell. This kept the grass growing until the
middle of November when the weather became exceedingly hot and a scarcity of
grass occurred.

SUMMARY AND CONCLUSIONS.

1. That it is possible to build up a profitable grade herd of dairy eattle by
using purebred bulls on creole cows.

2. In milk yield the grade cow compares most favourably with the pure*
bred, is hardier and more economical with feed.

3. The creole oow has no place in economical dairying.

4. The cost of rearing calves can be considerably reduced by feeding a
limited amount of whole milk and substituting a calf meal.

5. The cost of local feed stuffs is high, and the supply not dependable.

6. That with the improvement of breed, there must also be an improve*
tnent of the food supply.

7. That with a reasonable amount of drainage, the coastal pastures can be
Improved by fencing, manuring and rotational grazing. The carrying capacity
and nutritive value are increased and dairying can be considered an alternative
to rice farming.

A MILLING TEST ON SIXTY PADI VARIETIES.

D. W. DUTHIE, ph.d., p.i.c., Chemist.

AND

C. L. 0. BOURNE, Assistant Chemist.

I. Method op Testing.

One difficulty in padi selection and breeding work is that a variety which is
suitable from the point of view of cultivation i.e., yield, lack of “ shattering,”
strength of straw, etc., may give a high breakage percentage on parboiling and
milling. A method was therefore developed by which small quantities of the
different varieties could be tested under standard conditions of parboiling and
milling.

Soaking and steaming were carried out by a laboratory adaptation of the
method in general use in this Colony, and a high degree of efficiency was
attained on account of the smallness of the samples (up to 300 grms.). The padi
was placed in a conical flask, covered with water at 80"C (176°F), which
immediately fell to 60°C when in contact with the padi. The flask, with a
loose glass stopper, was left overnight (18 hours) in an electric oven, set at
60°C, which maintained the steeping water at 50 — 55 "C (120 — 130°F.). A
photograph of the steaming apparatus is given, showing how the steam is led
from a copper boiler through a glass tube which nearly reaches the bottom of
the inverted flask, the outlet for waste steam and condensation water leading
downwards from the neck of the flask. The padi was steamed for 4 minutes,
its temperature being about 100°C, as the steam was not under pressure. The
steamed padi was dried in the sun, but considerable difficulty was experienced
in standardising the temperature of drying. By a series of tests it was found
that breakage due to rapid' drying coqjld be avoided by sun-drying under a
muslin shade, thereby keeping the temperature of the padi below 38°C (100°F).
Drying was continued until the padi had a moisture content of 12 or 13 per
cent.

Milling was carried out in a small-scale machine manufactured by Messrs.
Guidetti and Artioli, Vercelli, Italy, in which small samples of padi (e.g., 100 grms.)
fan be hulled and polished in a manner which approximates to that in a large-
scale mill. The machine consists of a carborundum disc huller, a carborundum
cone polisher, and two fans by which the rice and hulls are blown from the
huller to the polisher, and then are made to pass repeatedly through the polisher,
until a suitable finish is obtained. The machine is driven by a Binall electric

144 AGBl6tft/fTTRAL JOURNAL OF BBlriSH OtrtASA. tlX 1

motor, and the air system also separates the hulls from the rice. The normal
procedure is to hull, winnow and polish in one operation, the time required for
100 grins, of padi being 2 — 3 minutes, but these processes can be carried out
separately, in order to find the breakage on hulling compared with that on
polishing, and also to find the amount lost in polishing. The latter method was
adopted in this investigation, the time of polishing being one minute. The
broken grains were separated by the hand grader which forms part of the mill-
ing outfit. It consists of a metal plate, with hemispherical indentations of
standard diameter (4.5 millimetres), suspended on wires and vibrated by an
eccentric drive. The broken grains are retained by the plate, which is readily
removed from its frame.

Conditions of steeping, steaming and drying were thus standardised as far
as possible, although of course, the rate of drying varied with the amount of
sunshine. “ White-belly ” was not found in any sample, so the method of par-
boiling was effective for all varieties. The parboiled padi was then hulled and
winnowed, and the breakage due to hulling was measured. The whole grains
were then polished for one minute, and the breakage and loss in weight duo to
polishing were fouhd in the same way. Replications of the tests showed that fine
distinctions of milling quality were not permissible, but the difference between
the poorest and best was sufficiently large to show up those varieties which are
likely to give a high breakage on large-scale milling. These differences would
probably be magnified under factory conditions, since the lowest breakage
percentages are small compared with those in commercial milling.

The test is thus of comparative value, and forms a useful adjunct to
selection work. It is not suggested, however, that an otherwise promising
variety should be discarded in the early stages of selection purely on account of
its reaction to this test. By applying the test in the later stages of variety trials,
when seasonal and environmental variations are being taken into account, it
should be of value in judging a variety before large scale distribution is carried
out. In addition to this, it might conceivably be used where strength of grain
is being considered in breeding work.

II. Experimental.

The table of results gives the figures for breakage due to polishing, total
breakage, length of grain (average of 10 grains hnsked by hand), and the yield
in lb. from 1,000 plants in the selection tests. The varieties are arranged in
three classes, long-grain types (over 7.3 mm.), medium-long types (0.9 — 7.3 mm.)
and medium grain types (below 6.9 mm.). In each class the varieties are
arranged in order of yield, since this property is the first consideration in
selection work. Sethi et al. (Indian J. Agr. Sci. Oct. 1937 p. 713) carried out
milling tests on sin varieties of Indian padi, using 30 lb. samples milled with an
Englefeerg huller, and they attributed their differences in milling quality to
seasonal factors existing at the time the respective crops matured^ and to the
post-harvest operations, such as drying, threshing, etc. In the present investiga-

Plate v.

Fig. 1 : — Apparatus for Steaming Padi

A. MILLING TfcgY ON SIXTY PaJM VabIETIES.

145

tioa these factors have been standardised to a great extent, since the plants were
grown, harvested, threshed and dried under the controlled conditions of selection
work. The breakages given by Sethi and his colleagues are high in comparison
with onrs, ranging from- 37 to 55 per cent., due in part to the fact that they
worked on a semi-large scale, with padi grown under field conditions.

Figures for loss of weight on polishing are not given in the table, as there
was very little difference between varieties, the range of figures being between
10 aDd 12 per cent. This shews, however, that there is an appreciable loss of
weight on polishing, and the breakage figures demonstrate that nearly all the
breakage occurs during polishing.

Table op Results.

Variety

Yield : lb. per
1,000 plants

Length of
Grain mm.

Total

Breakage %

Breakage on
Polishing %

Long Grain Types (over

7.3 mm.)

54—37 |

110.3

7.7

8.5

7.4

Padi Berbice

100.7

7.4

12.2

11.1

Sue

95.6

7.4

4.7

4.3

Jaisingh

92.9

1 7.7

' 6.3

5.8

53—37

88.2

l 7.5

| 8.8

7.7

D 254

85.6

7.4

2.9

1.6

D 259

85.1

8.0

| 11.6

10.5

51—37

84.6

' 7.5

| 6.9

5.9

52—37

80.9

7.6

11.8

10.0

13—37

80.6

7.5

14.1

10.5

D 90

77.9

7.7

5.6

1 5.1

8eymonr S

! 76.8

7.9

4.8

4.0

Nickerie Patna

75.4

7.4

6.3

5.5

D 89

71.9

7.6

6.8

6.1

D 162

69 4

. 7.4-

5.6

5.1

D 221

67.6

7.7

5.7

3.9

31—37

67.5 •

7.4

11.1

9.0

30—37

65.1

' 7.5

53 '

4.3

Ramjess

64.6

7.4

3.4 1

2.6

D 228

63.7

, 7.8 |

9.5 1

7.8

D 91

63.6

! 7.5

6.3

5.5

Demerara Creole

61,1

, 7.6

4.2

3.5

27*— 37

57.1

, 7.5

8.8

7.6

No. 76

56.9

1 7.6

5.0

4.2

No. 75

54.7

i 7.5 •

5.3

4.7

Kalyaman

54.0 ;

7.6

6.2

5.2

25—37

52.5 1

_ 7.7

10.9 *

7.0

Average for Long-grain types : Total breakage =7.3 (Range 2.9—14.1)
' Breakage on poli»hing=6.1 (Range 1.6 — 11.1)

166 AGBICtTI/TUBAJj JoTTENAL ofr BKITISH GTJIAJffA. flK, &.

Variety

Yield: lb .
per 1,000
plants

Length of
Grain mm.

Total

Breakage %

Breakage on
Polishing %

Medium-long Grain

7,3 mm.)

D 255

110.2

7.0

3.6

3.1

D 256

92.9

6.9

3,5

3.0

P 115

86.3

7.1

5.3

5.2

P 255

84.2

7.3

5.3

P 258

82.2

6.9

6.0

4.2

P 116

73 6

7.1

6.3

5.1

D 109

73.4

7.3

8.1

7.1

29-37

72.1

7.3

6.4

5.0

D 92

70.6

7.2

7.0

5.9

D 251

70.5

7.3

3.4

2.8

D 114

68.9

7.1

5.6

5.1

P 88 ,

63 7 '

7.3

7.5

6.7

II 7

61.2

7.3

7.1

5.5

Averages tor Medium Long-grain types : Tot^l breakage =5.1) (Rangel.3.5 — 7.5)
Breakag e on p olishin g 5 ^!.!) (Range 2.8 — 7 .1)

Variety

Yield : lb.
per 1,000
plants

Length of
Grain mm.

Total

Breakage %

I Breakage on

1 Polishing %

Medium Gram Types

(below 6.9

mm.)

P 257

106 2

6.3 1

2.4

1.7

17-37

89.8

6.7

3.5

3.1

Unity

88.3

| 6.5

1.1

0.8

19-37

82.6

! 6.6

4.0

2.7

15-37

82,4

6.7

3.9

2.9

P 247

81.3

6.5

5.1

3.6

P 108

76.0

6.6

1.6

1.0

23-37

75.7

6.6

7.0

3.9

D 250

73.9

6.6

3.4

1.8

18-37

73.1

6.6

5.1

3.5

P 246

71.6

6.8

3.8

3.4

P 99

70.9

6.3

4.9

3.4

P 97B

69.7

6.6

3.7

2.2

P 94

69.6

6.6

2.6

2.2

P 193

69.1

6.8

3.1

1.7

P 110

68.5

6.8

2.0

1.7

Bine Stick

62.6

6.5

1.6

1.1

No. 79

61.6

6.5

1.2

0.7

P 261

54.1

6.3

3.6

3.1

i P 262

45.5

6.6

4.2

3.9

Averages for Medium-grain types : Total breakage—3.4 (Range 1.1 — 7.0)

Breakage on polishing— 2,4 (Range 0,7— 3.9)

Plate vi,

Fig 2 Experimental Mill.

Left: Holier. Centre * Polisher. Riyht: Grader.

A MILLING TEST ON SIXTY PAW V ABIE TIBS. i 6?

III. Discussion.

It is striking that about 90 per cent, of the breakage and a loss in weight of
over 10 per cent, occur daring polishing. This shows the value of pure line
padi, since variation ill size of grain and in colour of cuticle would probably
make longer polishing necessary. On the other hand there were considerable
differences between varieties in the colour of the unpolished rice grains, and
thus it would be possible to cut down the time of polishing when working on a
commercial soale with certain varieties. This point is important in the
economics of rice milling, as it seriously affects both breakage and recovery.

As would be expected, the long-grain types gave on the average a higher
breakage than medium-long, the medium grains being the best of the three
classes. It is somewhat surprising to find that the shape of grain did not always
prove to be a dominant factor, since Demerara Creole, a scimitar-shaped grain,
gave a low breakage for its class.

Of the long-grain varieties, Sue, Seymour S, D 254, Ramjess and Demerara
Creole appear to give the hardest grains on parboiling, but they are not marked-
ly superior to several others, such as D 90, D 162, D 221, 30-37, No. 76 and No.
75, which show only a slightly higher breakage. It is difficult to pick out the
best variety as regards milling properties, but several gave high breakages, which
leads to considerable doubt as to their suitability for commercial extension. Of
these, Padi Berbice, 13 — 37, D 259, 52 — 37 and 31 — 37 all gave over 10 per cent,
breakage.

On the whole, there is not much to choose between the medium-long varieties.
Rven D 88, with 7.5 per cent, breakage, is not greatly inferior to D 251, which
gave the lowest figure (3.4) of this class. Other varietal properties would
probably assume more importance in the selection and breeding work in this
class. The medium-grain padis, with an average breakage of 3.4 per cent,
includes several varieties which repeatedly gave practically no breakage, since
figures under 2 per cent, could be accounted for by bird damage and insect attack.
From the miller’s point of view, it would be preferable to concentrate on types
with grain length below 6.9 mm., but of course, market requirements and other
economic and biological factors might outweigh this consideration.

Undoubtedly, the most important factor in breakage is the rate of drying
both in the field and on the factory drying floor. In our preliminary work we
had considerable difficulty in ensuring that drying would take place at a reason-
able rate without being too rapid. The effect of too rapid drying will far
outbalance the differences between varieties which have been noted here, but it
should be remembered that those varieties which showed up badly in this test,
did so under conditions which were nearly ideal. It seems reasonable to argue,
therefore, that varieties which gave comparatively high breakages would be
difficult to handle under factory conditions, and thus the test would be of value
in eliminating unsuitable varieties. On the other hand, it does not follow that
every variety which is suitable on these standards will retain its plaoe when

AafeicmAtifcAt JOt&hAL o* Bfeitasb cAtju&a.

tlX,!

subjected to large-scale milling. In our first tests the rate of drying was too
high for most varieties, but one or two seem to withstand even severe conditions,
and further work along this line will be carried out in order to find which varie-
ties can be dried rapidly without excessive breakage.

Acknowledgment.

This investigation was suggested by Capt. F. Burnett, Deputy Director of
Agriculture, and thanks are due to him, and to Mr. P. A. Cban-Ohoong, Assistant
Plant Breeder, for the padi samples and for the yield and grain-length figures.

Plate vii,

Fig. 3:— Close View of Grader.

SELECTED ARTICLE

THE CULTIVATION OF CAJANUS CAJAN AND THE
METHODS OF PREPARING MARKETABLE DHAL*.

P, M. GAYWALA, M.Ag„ (Bombay)

Demonstrator in Cultivation , Farm School, Peradeniya.

Cajanus cajan ( —C. indicus) is considered to be one of the most promising
legumes at the present time. It is one of the favourite crops of the average
village cultivator for a variety of reasons. The Indian farmer has recognised
its value in the light of his accumulated experience extending over several
centuries. The scientific study of agricultural problems during recent years has
confirmed its recognition by the cultivator. It occupies a predominating
position among the pulse crops of India and is used as a restorative, rotational
or mixed crop.

Prom the point of view of keeping the soil in fertile condition in dry and
arid tracts, there is hardly a leguminous crop that can stand comparison with it.
Being a drought resistant crop, it grows successfully in tracts receiving annual
rainfall of 25 to 30 inches or even less. It has been known to have grown
successfully in some dry seasons when other crops have failed. It has a deeply
peaetrating root system which enables it to open up any hard set soil to a great
depth thus aerating the soil and bringing it to a much finer state of physical con*
dition for the subsequent crops. Throughout its growing period and particularly
during the later stage it sheds a large amount of leafy material which definitely
enriches the soil in valuable organic matter. Like other leguminous crops, it
also fixes atmospheric nitrogen in the soil. From the economic point of view,
the crop possesses some commendable features. The plant yields seed which
affords a nutritious article of food. The leaves, the husk of pods and the seed
ooats, which are all by-products of the crop, are utilized as excellent feeding
stuffs for the milch and draft cattle of the farmer. The stalks supply him his
domestic requirements of fuel. The cultivator usually sells the surplus grain
for which he finds a ready market. The crop has therefore many desirable
features in its favour, viz., it furnishes food for the farmer’s family and cattle,
provides fnel, and helps to maintain the fertility of the soil while* it is also a
money crop.

•Reprinted from the *' Tropical Agriculturist " of Ceylon, Yol. XC, No. 4, Apnl lWb,

170

AGRICULTURAL JOURNAL Of BRITISH GUIANA,

[IX, 3,

The pulse is used in a variety of ways but its ohief use is in its split form as
dhal Dhal contains as high as 18 to 20 per cent, proteins and is therefore of
definite value to a vegetarian population. The tender pods of this crop are
extensively used as a vegetable in the same manner as garden peas. An Indian
cultivator living near a market sells the first part of his crop in the form of
green vegetable pods and allows the pods which form later to mature for the
production of seed.

The plant has further uses. During recent years it is being developed,
particularly in the United States of America, as a leguminous fodder crop and
in this respect is likely to rival lucerne in importance. It does not require such
careful management as lucerne. Being a drought resistant and hardy crop it
grows well in any soil under adverse conditions with little attention. It
matures for fodder comparatively rapidly and is capable of being utilized as a
perennial fodder crop. Live stock and poultry relish the crop. It has also
been recommended as a green manure crop. According to leaflet No. 14 of the
Ceylon Department of Agriculture it may be grown as a green manure crop
interplanted with young rubber and coconuts in tracts receiving less than 100
inches rainfall. However, as a green manure crop for annual crops it does not
compare favourably with other well known green manure crops on account of
the comparatively slow habit of growth and the large proportion of woody
material in the plant. It is also grown as a shade crop, cover crop, and
occasionally a wind-break hedge plant. In Assam, for example, it is grown as
a border crop round sugar oane fields more for the protection of the cane crop
than for the yield of its seeds. In such cases the dry stalks serve the purpose
of a much needed fuel in boiling the cane juice.

Varieties.

The plant is known to have a large number of varieties with slightly
different characters, growing under varying conditions in many parts of India.
The recent survey of the varieties of this plant by the Imperial Economic
Botanist at Pusa (Scientific Reports of the Agricultural Research Institute, Pnsa,
1928-29, page 21) shows that the number of distinct types obtained was 107 in-
dicating great variations in height, habit of growth, the time of maturity, colour
of flower, colour and shape of pods, and the size, colour and shape of seeds. The
varieties, however, can be subdivided into main groups. The first comprises the
peieunial type which assumes a tree-like appearance and is allowed to grow for
more than a year. From the point of view of yield of seed, this variety yields
a fairly good first crop but the yield in subsequent years falls considerably.
This type is used more as a shade, fodder, cover, or hedge plant than for seed.
The small or annual type is mostly grown as a field crop for its seed. The size,

t pe and colour of seed vary in different varieties. The white seeded variety
ich is grown in Gujarat, Western India, yields a very fine quality of dhal
fetching the best market price. The red or the brown seeded variety does not
grow well in the heavy black cotton soils of Gujarat and is mostly confiped tp
the lighter type of soils soptfi pf Bombay,

THB CULTIVATION OF CAJANUS CAJAN.

171

Soil and Climatic Requirements.

Cajanus cajan is grown mostly in mixture with a large variety of crops
under a wide range of soil and climatic conditions. This fact indicates that the
plant is quite capable of adapting itself to widely variable conditions. Under
dry conditions'it comes to maturity fairly quickly. Under humid conditions as
would be expected the crop tends to produce luxuriant vegetative growth.
Cloudy weather and rain at the flowering time causes defective fertilization and
the pod-caterpillar appears on the crop damaging the growing pods. Stagnant
water in fields is definitely harmful to the crop.

The wet zone of Ceylon is rather unsuited to the successful cultivation of
this crop for seed production. The climate is likely to prove too humid and the
flewering is liable to be affected. In the dry zones subject to one monsoon only
and where the rain has almost ceased by the time the plants come into flower,
the crop would naturally grow well. Moreover, there is every possibility of
finding a strain suitable for any given local conditions from among the large
number of varieties growing under a wide range of climatic conditions in
India. If the aim is not the production of seed, the plant may be grown in the
wet zone and will produce luxuriant vegetative growth for purposes of fodder,
shade, cover, hedges or wind-breaks.

Methods of Cultivation.

In India the Cajanus cajan crop is usually grown as a mixed crop. It is
sown in widely spaced lines as a subordinate mixture with other crop or crops
of a shorter growing period, such as sorghum, maize, bulrush millet, other
millets, gingelly, ground-nuts, &c. These intervening crops, being of a shorter
duration than Cajanus rajan, are ready for harvesting first. The Cajanus cajan
achieves its full growth after the maturity or removal of this intervening crop
and is then able to utilize all the additional space made available between the
rows. * .•

Because of the fact that it is raised as a mixed crop, the soils available for
this crop naturally vary with the requirements of its accompanying main crop.
For example, with sorghum it will occupy a heavier clay loam type of soil ;
with millets, groundnut and gingelly it will occupy a lighter type of loam to
sandy loam soils. Usually it does not require manures but if grown on a newly
opened or well manured land, growth is luxuriant. As with any other legum-
inous crop the soil for this crop should not be deficient in lime. The character of
preparatory tillage will be determined by the requirements of its associated crop.
In India it is usually sown at the commencement of the south-west monsoon in
June or early in July and is ready for harvesting by Feb^pary or March.
The other crops grown in association are usually harvested by the first week of
October. The period from October to March is more or less dry and rainless.
The crop does not require any irrigation during this long dry period because it
is able to draw its own moisture requirements from lower depths with the help
of its deeply penetrating root system.

172 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 3.

In a common and typical form of mixture Cajanw cajan occupies every
fourth row of the mixed crop which is either drilled by a special attachment to
the oountry plough called Moffan or is dibbled behind the country plough in a
line just opened by it. The Cajanua cojan will thus be in rows 4 to 6 feet
apart depending upon the type of its associated crop and the spacing given to it.
The seed rate with this type of mixture varies from 1$ to 3 lb. per acre. In
the case of an unraixed Cajanus crop, the seed rate would amount to about
8 lb. per acre. In South India where it is sometimes grown mixed with
gronndnuts, the distance allowed between the two rows of Vajanus eajan is
10 to 23 feet. The object of keeping it so wide apart is to keep the groundnuts
as far as possible free from shade. The seed rate in this case is naturally
very low and depends upon the actual spacing.

After germination is completed the plants have to be thinned in the
rows to a space of about a foot apart in light soils. In good and deep soils
spacing may be done at 2 feet apart.

During the first 4 to 6 weeks, the crop shares the useful intercultivation
given to the main crop. The crop is theD usually allowed to take its own
course. There is a belief in India that the more this crop is trampled when
the main crop is harvested, the greater will be the subsequent development of
branches, flowers and pods. When grown with groundnut in South India, the
soil has to be dug over for removing the groundnut and this serves the purpose
of a final cultivation without extra cost. If seed production is the object, the
crop is allowed to remain standing in the field till the pods dry on the plants.

When it is used as a perennial crop, the branches are cut off for feeding
cattle whenever required or at regular intervals. At the close of the season,
the plants are pruned to about 2 feet above the ground. With the advent of
the new season’s rain, *he pruned plants will start growing again. Thus the
crop can be made to yield a large amount of leafy material in humid tracts for
3 to 5 years. It is, however, equally easy to renew the sowings every year.

Harvesting and Threshing.

The crop is harvested by cutting the whole plant close to the ground by
means of a sharp sickle. The actual treatment of the plants after they are cut
depends upon the prevailing local conditions. Where there is risk of damage
by rains or by thieves, the plants are tied into small bundles soon after they
are cut and carted to the threshing floor. Bundles are then allowed to
remain there for a few days till the green leaves left on the plants completely
dry off and the ripe pods open slightly. If the possibility of damage by rain
or by thieves does not arise, • the harvested plants are collected and left in
the field for a day or two till they are fairly dry and then carted to the
threlhing floor early in the morning to avoid shedding of seeds fropa the

THB CULTIVATION OF CAJANUS CAJAN,

173

The threshing is usually done by vigorously shaking the dry plants. A
good many pods and seeds with leaves are thrown out. Those that do not
drop by shaking are finally beaten with strong bamboos or wooden flails.
When everything has dropped from stalks the material is farther beaten by
sticks or trampled under the feet of bullocks which completely separates the
grain. The grains are further cleaned from the chaff by subsequent winnowing.
The chaff so separated is a good feeding stuff for draft cattle. The stocks are
mostly used as a fuel. Thin or straight stalks or branches are used for roofing
or for making the sides of the bullock carts.

Yields.

As a fourth row mixture, the yield of seed ranges from 300 to 600 lb.
per acre depending on the type of mixture adopted and the soil and climatic
conditions under which it is grown. A bushel of seed usually weighs 56 lb.

Method op Marketing in India.

The seed produced by village cultivators is usually brought by them in
cart loads to primary markets located in small towns near by. Here the
professional dhal-makers locally known as golas buy the produce with a view
to making dhal out of it. This professional class of golas is found in most of
the small towns all over India. To them dhal-making is a fairly profitable
small scale industry extending over the greater part of the year. They are
a class of people with limited moans and work with the small hand-operated
splitting mills run by hired labour. The methods of milling slightly vary in
different districts. A few enterprising golas beep several such mills and
work with a larger labour force during periods of demand. Large scale modern
mills operated by mechanical power have not been erected to any appreciable
extent chiefly because the people engaged in this industry are of limited means
and also because most of the villagers are producers as well as consumers of
dhal. A few power mills are to be seen in some large towns. Some of the
cultivators who appreciate the value of home-tfiade products make their dhal
from their own farm produce. To them the necessity for selling the grain to
golas and later buying the dhal from them does not exist. The dhal produced
by the cultivators themselves is of good quality because of the great care
exercised by them. Most of the dhal produced by the cultivator is for the
use of his own family and only the small surplus is disposed of. As will be
seen later, the process of dhal-making is quite simple, and every cultivator
can prepare his requirement with little effort unless he has a more important
call upon his time.

Preparation of Dhal.

The particular method of preparing dhal adopted has 1 Sn important
bearing upon the final quality of the commercial product. It may therefore
"'fee useful to djscuBS flrBt the points which decide the quality of dbal. Dhal is
chiefly used as a food in boiled form. A good quality of dhal should be easily

174 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 3.

and quickly reduced by boiling to a homogenous semi-liquid mass. After
boiling it should not continue to retain its original form or shape and should
not show any unbroken hard pieces. If the dhal becomes soft in a reasonably
short period of boiling, the flavour and taste of the cooked product is
better than if boiled for a long time. This quality of softening after briefc
cooking should be retained during the storage period ; this is the second
important consideration of quality. Any sample of dhal, therefore, which
cooks soft quickly and retains this quality during a fairly long period of
storage is regarded as of good quality.

There are two well defined methods of preparing dhal in India. Each is
practised under certain local conditions and has its own advantages and
disadvantages.

The first is the dry method which is chiefly used in Gujarat and parts of
Northern India. The dhal obtained by this method softens rapidly on cooking
and the resulting flavour is very good. This method of preparation is costly
and the proportion of broken dhal is comparatively more. The dhal obtained
by this process is of perfect shape of a half -moon. It realizes a very good
price in the market.

The second is the wet method in which water is freely made use of.
Something like controlled malting takes place. The resulting dhal is hard to
cook after a short period of storage and is not then fully reduced to a
homogenous semi-liquid mass even after prolonged boiling. The flavour is not
So good as in the dry method. The method has the advantage of cheapness.
Another advantage in its favour is that the proportion of broken dhal is very
small and therefore the percentage of dhal recovered by this process is much
greater. The dhal obtained has a semi-round shape depressed in the centre.
This process is extensively used in South India extending up to Bombay Deccan
with slight local modifications.

Both processes require ample sunshine for thorough drying of the seed
preparatory to dhal making. Therefore the availability of bright sunny days
is the first important essential for successful dhal-making. Such conditions
obtain in the dry zones of Ceylon and thus make possible the creation of a
small village industry providing occupation throughout most of the year.

The splitting mill used in both of the above methods is a mill with two
circular stones, one of which rotates round an axle fixed perpendicularly at the
centre of the lower or bottom stone. The axle passes through the upper stone
which is provided with a centre hole through which the grains are fed into the
mill. There is another small hole near the circumference of this upper stone
where a strong peg is fixed. By means of this peg the upper stone is made to
rptiite round the axle. The pulse seed is thereby split up into two halves or
cotyledons and tbe seed coat is separated, The pulse seeds are ted through the

TOT CULTIVATION OB' CAJANTTS CAJAS.

175

hole in the centre and the split dhal is collected below ronnd the stone. The
stone mill used in Gujarat generally weighs about 120 to 150 lb, and costs about
Bs. 15 to 25 depending on the quality of stone used.

In some places a mill of larger sise is used but has to be rotated by two
persons working simultaneously. It is provided with two strong pegs fitted in
two boles at opposite points on the upper stone near the circumference.

Dry Method of Making Dhal.

This process can be conveniently divided into the following seven stages

(1) Preliminary sun-drying. — The seeds are exposed to hot sunshine for
three to four days. If the temperature is below 90°F., drying may have to be
prolonged for a longer period.

(2) Preliminary and partial splitting of grains. — This is usually done
at noon. The grains are taken from the drying place and they are fed to the
splitting stone mill in a hot condition. The grains are fed rapidly in large
quantities at a time. The object is to get the seed coat pressed and effect some
cracking of the seed coat while the seeds are moving in a hot condition between
the stones. Along with cracking of the seed coat, about half the seeds split
into cotyledons but their coats are not removed. The partially split seeds with
cracked seed coats at this stage of the process are known as dol. The above two
stages of the process can be carried out soon after bringing the produce from the
fields if desired, or at any other suitable time.

(3) Treating the dol with vegetable oil and storing it. — The dol so
obtained is not usually made into the final dhal immediately. It is treated
with a small quantity of vegetable oil at the rate of about 2 lb. per 100 pounds
of dol , and stored for varying periods. If the storage period iB to extend for
more than a month castor oil is used ; gingelly oil being used if the storage
period is less than a month. Storing of dol treated with oil for at least a fort*
night is considered necessary. The ohief object pf treating dol with oil and
storing it for some time is to allow the slightly cracked seed coat of the pulse
to absorb the oil making the seed coat soft and thus assisting considerably in
the final splitting of the pulse into dhal and the removal of the seed coat from
the split dhal. The treated material should remain oily during the entire period
of storage. The variation in the storage period offers an opportunity to distri-
bute the dhal making business over a longer period of the year so that it can
be done at convenient times.

(4) Second sun-drying. — After the storage period is over, the oil-treated
and stored dol is again exposed to sunshine for two to five days depending upon
the prevailing temperature.

(5) Final splitting. This is also done at noon. The material is fed to
the same stpne mill, preferably in a warm condition at slower rate and in
smaller quantities than during the preliminary splitting. During the course of

170 AGRICULTURAL JOURNAL OP BRITISH GTJtANA. [IX, 3.

this operation the seed coats will separate, and a large portion of the nnsplit
material will also be split up. Daring splitting the mill mast move compara-
tively slowly as otherwise a great proportion of the dhal is likely to be broken up.

(6) Sieving mid winnowing . — The split dhal iB then separated and cleaned
from the seed coat by sieving and winnowing. The small broken pieees
are also separated as far as possible.

(7) Treating finally with vegetable oil . — The dhal is then finally treated
with castor or gingelly oil at the rate of about 2£ lb. per 100 lb. of dhal and is
ready for sale. The final oil treatment is intended to preserve the quality of
dhal, prevent insect attack and make it of attractive appearance.

This method of dhal-making is rather expensive because of the nse of
vegetable oil at two stages, and the extra labour required in double splitting.
Moreover, the proportion of broken dhal is much higher. From 100 lb. of seed
about 66 lb. of clean good quality dhal is obtainable. The rest is broken
material and the seed coats.

The outer covers of the seed in admixture with the small broken pieoes of
dhal obtained^ a by-product in dhal-making is known under the name of
chuni throughout India, It is a favourite concentrated foodstuff for dairy cows.

Wet Method of* Making Dhal.

The seed collected by professional dhal makers is allowed to soak in water
for about six hours either in tubs or in well constructed vats. The free water
is then removed or drained away. At this stage, fine, well sieved earth prefer-
ably of the red laterite type is added at the rate of about 5 lb. per 100 lb, grain and
well mixed. The mixture of soaked grain and moist earth is heaped up and
kept in that condition for the night. Next morning, the heap is broken up and
the material exposed to the sun for drying. The drying continues for a day or
two according to the temperature. After thorough drying the seeds are again
mixed up with a thin turbid mixture of red soil and water and heaped up for
the night. Next morning they are removed and thoroughly dried. They are
then sieved and winnowed to remove the earth and other impurities. The seeds
are finally split into halves in the stone mill.

Cultivators who prepare their own dhal adopt a slightly modified method
which is more laborious and takes more time, but the dhal obtained is of some-
what superior quality. Instead of soaking his seed in water the cultivator
prepares a thin mixture of red laterite soil and water and applies this earth
solution to his seed at repeated intervals of about an hour throughout the day.
Each time the earth solution is well mixed up with the seed by repeatedly
timping over the heap. By this method the seeds do not absorb moisture in free
water but the absorption of moisture is being effected gradually in several
stages. The heap remains undisturbed throughout the night. In the morning
the seedis exposed to ih# sun for drying and then finally split np into dhal.

TfiB CULTIVATION OF CAJANUS CAJAN.

177

The professional dbal makers allow the seeds to absorb a larger quantity of
moisture and the seeds swell considerably. On drying such seed the shrinkage
is great and therefore the resulting dhal assumes a marked depression in the
oentre. In the cultivator’s method, as the soaking is gradual and according to
requirements, the resulting &hal does not have so prominent a depression in the
centre.

By the web method, 100 lb. of seed yield about 80 lb. of marketable dhal.
The breakage of dhal is low. The object of wetting and drying is of course, to
produce a contracting and expanding action on the seed coat which, as a result,
offers much less resistance when the seeds are being split in the mill.

Concluding Remarks.

A close observation and study of the conditions under which Cajanun
cajan is cultivated in India indicates that some of the varieties of this plant are
capable of successful cultivation for seed production in the dry parts of Ceylon.
The small scale processes of dhal-making described above are fairly simple and
do not require expensive outfits. The requisite number of dry sunny days are
available in the dry zones for the preparation of dhal. The local consumption
of dhal in Ceylon is considerable. Under the circumstances, it is quite possible
with some effort and attention to produce good quality dhal for local consump-
tion. The crop itself is likely to prove an important rotational crop or an
appropriate mixed crop in the village agriculture of this country, while the
preparation of dhal offers an opportunity of being taken up as a new and
profitable cottage industry in the dry zone.

REPORT,

The fifteenth meeting of the advisory board of

AGRICULTURE.

Present.

The Director of Agriculture

The Deputy Director of Agriculture (ag.)

Hon. F. J. Seaford, O.B.E.

„ Peer Bacchus

,, J. W. Jackson ^

„ R. E. Brassington
Mr. W. H. Richards
Mr. S. Andries

' with

Capt. J. F. Irving, M.C.

Absent.

Mr. R. B. Hunter.

Chairman

Members

Secretary

Member

An excuse for non-attendance was tendered for Mr. R. B. Hunter.

The minutes of the last meeting held on March 21, 1938, which had
previously been circulated, were confirmed.

The Chairman referred to the following matters arising out of the minutes :

(1) Cattle Branding Ordinance. No further communication had been
received from Government but the intention so far as he knew was not to
proceed with the amendments. Hon. F. J. Seaford said that enquiries had
recently been made by the Rupununi ranchers as to the placing of brands on
animals in such a way as not to prejudice the value of the hides and Govern-
ment had been written regarding the proposed amendments. He asked that
if the matter were again referred to the Board it should receive early
attention. Hon. Peer Bacchus remarked that from his experience a large brand
was useful in the country districts as it enabled owners to recognise their
animals from a distance. Members thought that changes as regards size and
position of brands might apply to Rupununi cattle only at first.

(2) Berbice Exhibition. It was proposed to make arrangements for
holding the postponed show next year.

(3) Glasgow Exhibition. The Department had forwarded agricultural
products in co-operation with the Departments of Forestry and Lands & Mines.

REPORT.

179

(4) La Belle Alliance . The Director of Public Works was proceeding with
the drainage of the area and a start was being made with the sand reef for
buildings and stables, etc*

(5) Government Veterinary Surgeon . Consequent on the retirement of
Major T. Bone, Mr. H. A. Fraser had been appointed to act in his place.

(6) Reduction on Railway Freights . The Deputy Director had gone into
the matter with the Managing Director, Transport Board, who had supplied a
tariff with all the information on the subject.

Unfortunately, the Managing Director had stated that he could hold out
little hope of any decrease ; rather there was every chance in view of the
increased cost of wages, etc., of the possibility of freight charges having to be
increased. It was unanimously agreed that Hon. Peer Bacchus and the
Secretary should see the Managing Director on the subject,

Coffee Committee's Report. The Chairman said that the report of the Coffee
Committee had been submitted to Government, but as this was not yet
published he was not in a position to discuss the matter at present.

Fine-curing of Tobacco. The Chairman reported on the results that had
been obtained in connection with the tobacco flue-curing experiment. About
£ of an acre had been planted at Sophia and a small flue-barn had been built.
The results obtained had been fairly satisfactory and the two local tobacco
factories had stated that they were prepared to buy a limited quantity of local
tobacco but would not commit themselves beyond a certain figure, as this
would depend entirely on the quality of the article produced. It was essential,
however, that whatever is grown must be properly cured, packed, etc., and as
there are many defects still to be overcome — although the local factories have
stated that the leaf so far supplied is the very best they have seen locally — the
Secretary of State had been approached for assistance from the Colonial
Development Fund Advisory Committee to obtain the services of an expert in
flue-curing methods and barn construction. 'Jhis officer would be of great
assistance in the proper construction of barns and would be available for
instructions in the principles, practices and technical aspects of cqring tobacco*
The Board were unanimously of the opinion that the project, which appeared
an encouraging one for the creation of a minor industry, should be helped in
every way possible although the question of offsetting the revenue loss through
customs duties which was raised by Hon. F. J. Seaford, would, no doubt,
have to be considered at a later date.

Fruit c£ Vegetable Conference. The Chairman stated in connection with
the Fruit and Vegetable Council Meeting at Trinidad, he had introduced a
motion recommending that the intercolonial fruit and vegetable trade be care*
fully investigated by the Governments concerned, both from* the commercial
as well as the quarantine aspects, with a view to its proper organisation and
control. A* copy of the resolution and the related correspondence had been

1#6 4 Agricultural journal of britisr guiana, [IX, 3.

forwarded by Government to the Georgetown Chamber of Commerce and this
body had decided to raise the question at the next meeting of the Associated
Chambers of Commerce to be held shortly in Trinidad.

Bananas . The Chairman said that he regretted to have to report adversely
on the progress of the banana plots both at Middlesex and Supply. The losses
sustained from Panama Disease at Middlesex to date were approximately 30%
of the stools, while Leaf Spot disease was still very active in spite of spraying.
Of the bunches reaped to date only a small percentage wore of the 44 count
bunch’ 1 class i.c., 9 hands ; 7-hand bunches were fairly common. Mr. Richards
asked what was the amount placed on the estimate for the work and was
informed that $750 had been allocated this year. He said he considered that
matters had gone far enough and the plots should be immediately closed down,
as it was a pure waste of money to go on further with the experiments. The
Chairman said he hardly liked to suggest this step as false statements were
being made that the Department of Agriculture did not want to see a banana
industry, although the whole subject had been fully ventilated in the Legis-
lative Council. It was agreed that a memo, should be published on the results
so far obtained and that Government should be informed that in the opinion of
the Board further expenditure did not seem justified.

Shipment of Limes. The Chairman reported that recently a shipment of
20 crates (about 3,200 lruits) of green limes had been made to Canada for which
tbe sum of $24.58 had been received. The expenses including freight, cost of
crates, etc., had amounted to $19.24. The small balance would leave little
actual profit to the North-West grower on whose behalt this effort was made.

Anthrax. The Chairman reported that he regretted to announce that
Anthrax had broken out in the County of Borbice, at Pins. Bohemia,
Susannah and Hermitage, as well as at Pins. Palmyra and Seawell. Every
effort- was being made by the Department in collaboration with the Police
authorities to control the spread. The Medical Department also was involved
and had taken steps to prohibit the sale of milk from the infected areas. He
feared that the Veterinary Preventive Measures Vote would be inadequate as
special constables had to be employed to control cattle movements, but this
could not be helped under the circumstances.

Livestock . In connection with other Livestock matters, the Chairman
mentioned that arrangements had been made for a bull pen to be erected
shortly at Whim, Corentyne, and he also hoped to place some pure bred
poultry and a purebred boar there. He further stated that as export of
poultry and eggs had been taking place from Berbice to Trinidad by the small
Dutch steamers calling at Springlands and New Amsterdam, the time seemed
opportune tor creating additional interest in poultry rearing. He was glad to
announce that it was the wish of a number of interested persons to resuscitate
me Poultry Association and a meeting was being held in this connection on
August 12, at 4.30 p.m. to which he welcomed members of the Board. This
was considered a step in the right direction.

Arrival of Rice Mill Engineer . The Chairman referred to the future
visit of Mr. Parker, rice mill expert, whose experience in connection with Rice
Mills elsewhere should prove of great benefit to the rice industry in this
Colony.

District Agricultural Committees. The Chairman sought the advice of
the Board as to whether the need any longer existed for District Agricultural
Committees, of which there were two, in view of the fact that there was now a
properly constituted Advisory Board of Agriculture, as it meant considerable
duplication of work. Several members who served on such District
Agricultural Committees agreed that they no longer served any useful
purpose. The leeling was that they should be discontinued, but
the question of publishing the minutes of the Board might be re-opened.

Information for Colonial Empire Marketing Board. The Chairman in-
formed the Board that notes had been prepared and submitted to Government
for the Colonial Empire Marketing Board on the various products of the Colony
for which remunerative markets were argently required, e.g. y coffee, plantains and
by-products, cassava and by-products. The position in regard to rice had also
been dealt with and the need for help in the utilization and disposal of fruit pro-
ducts, juices, etc., had also been emphasised.

Economic Survey of Cane Farming . Certain figures in an article published
in the Agricultural Journal , by Mr. H. D. Huggins in connection with cane
farmers’ yields were questioned by the Hon. B. E. Brassington who considered
that the results shown were too high. The Hon. F. J. Seaford said it was possi-
ble that the figures were a misprint. Mr. Huggins who was present by invitation
said he considered the figures were substantially correct from information ob
tained by the survey method direct from the farmers, but he would go over
them with a view to making any corrections if necessary.

Malva fibre . Attention was called to a note winch appeared in the u Daily
Argosy” about Malva fibre in which it was stated that the Department of Agri-
culture had put a stop to a possible successful enterprise in 1929.

The Chairman stated that the early records of the Department showed that
interest had been taken in Malva fibre for some time prior to 1929 and that this
particular plant — Malachra capitata — had been tried out commercially in many
countries, notably India, but it had been given up as hopeless. The following
note by Sir John Harrison in 1925 setting out the position was then read; —

44 The reasons why Malachra fibre has not been developed commercially
are simple ; (a) low yield of fibre from the stems j (b) the great difficulty of
separating tho commercial fibre from the stems by retting and beating. The
beating has to be done by hand, no machine having been invented for this pur-
pose.

44 I have recently had samples of Malachra fibre prepared at the Botanic Gar-
dens from pitots growing at Sophia Station, The yield of clean fibre was rather

18& * AGRICULTURAL JOURNAL OP BRITISH GUlAltA. [iX, 3.

less than 3 per cent, of the weight of green stalks. The cost of gathering the
stalks, retting them and separating the fibre by hand labour was somewhat oyer
$708 per ton of the fibre obtained.

“Personally, I fail to perceive that we are missing anything beneficial to the
Colony by not undertaking the commercial exploitation of a fibre product the
production costs of which are $708 per ton in British Guiana and which issaleable
in London at £60.”

Since that minute was written by Sir John, further trials had been made
by the Department but results were not such as to justify immediate commercial
exploitation. The plant occurs wild in the Colony, but under cultivation, even
when thickly seeded, does not establish itself in an even stand, while the stalks
produced are of varying lengths and inclined to branch. The files show that a
certain individual in 1929-30 approached Government with proposals covering
the cultivation of 100 acres, using as a basis of his yield figures the returns from
65 selected plants. It was explained to him that it would be very unwise to
base conclusions on such a small number of plants and that before embarking
on an extensive layout, he should arrange to cultivate say five acres under the
aegis of the Department of Agriculture. Government approved of this and the
individual .was so informed. The Agricultural Officer in the North West District
was instructed to co-operate and give every possible assistance and advice to the
venture but the person concerned allowed the matter to slide and took no action.

The Board agreed that this explanation should be recorded in the minutes.

The meeting then terminated.

Note*

Padi and Riee Production in India and Burma. — In order to appreciate
and to make a comparison of the acreages, etc., under padi cultivation in India
and Burma with this Colony, the following is a short pr6cis of a report taken
from “ Agriculture and Animal Husbandry in India, 1935-36 ”,

Padi occupies about 35 per cent, of total cultivated area in India and in
1935-36 the estimated area was 81,841,000 acres producing 27,902,000 tons of
rice. Rico accounted for ninety-one per cent, of the total quantity of food-
grains and flour exported during 1935-36, In 1935-36 the production in India
proper was 22,843,000 tons and in Burma 5,018,000 and the exports were 191,000
tons for India proper and 1,213,000 tons for Burma. The exportable surplus is
derived almost entirely from Burma. Burma was responsible for eighty-six per
cent, of the total tonnage of rice shipped overseas in 1935-36. In British Guiana
(1936 census) 62,856 acres were reaped, producing 36,348 tons of rice, whilst the
total rice exports for the same period were 20,559 tons.

One of the main activities of the provincial departments of agriculture in
India and Burma with regard to rice is the distribution of improved strains to
the cultivators, the total area under improved varieties being 3,667,097 acres in
1935-36. Rico research is now being conducted on a wider scale than ever,
chiefly as the result of finances provided by the Imperial Council of Agricultural
Research. A Standing Committee on Rice consisting of forty-five members was
constituted during the year on the lines recommended by the Crop Planning
Conference, 1934.

BENGAL contributed 25.8 per cent, in area and 28.8 per cent, in production
of tho total Indian crop. The reported area^for the year, 21,092,000 acres, was
pearly the same as in the previous year, but the production, 7,208,000 tons, had
gone down by nearly twelve per cent. Plant-breeding work on rice is carried
on at various stations and special attention is paid to the propagation of varieties
and strains recommended by the Department. The number of seed-farms
increased from 334 to 369, during the year, the area increasing from 3,000 acres
to 3,025 acres. At the headquarters of the Economic Botanist, 2,075 types of
highland aus (autumn paddy), transplanted union (winter paddy) and other
rices' were under observation. The most promising of these are usually picked
out by preliminary observations for detailed yield tests. During the year thirty*
four selected varieties were under yield trials. A number of hybrid progenies
were compared against the parents for hybrid vigour. A .large number of
generations of crosses were under study. Histological studies on the distribution
of mechanical tissue in the straw, were continued on materials from rices with
lodging an<f erect habits and of their crosses. Results reported previously—

184 , AGRICtJLTCft AL JOURNAL OF BRITISH GUIANA. [iX, 3.

that copper sulphate treatment preserves the viability of seed during storage—
are found to hold good only when the treated seed is stored in air-tight recepta-
cles, Analyses of paddy and rice samples and oooking tests were carried out in
connection with the co-ordinated scheme of marketing survey in rice initiated by
the Imperial Council of Agricultural Research, Due to bad season and persistent
drought several of the yield tests had to be abandoned. At the Bankura station
several cultural and manurial trials were continued. In a complex experiment
dealing with broadcasting, dibbling and transplanting with two ages of seedling,
both dibbled and broadcast sowing gave a significantly higher yield than
transplanting and between the two sowings, dibbling was better than broad-
casting. The pot experiment with regard to the bost time of applying Nicifos
showed that its application at a much later period than transplanting time is
beneficial. Increased doses of Nicifos, were, as in the previous year, more
effective on yield tillering than smaller doses.

The province of BIHAR and ORISSA contributed 16.5 per cent, in area and
14.8 per cent, in production of the total crop in India. Scientific work is carried
on in the central station. The substations deal with simple selection in local
varieties and in addition arrange for the trial of strains evolved at the central
Station. Nearly 5,000 samples have been collected from different parts of the
province aqd are being grown and examined with a view to eliminating dupli-
cates and recording morphological characters. Selection work on types suitable
for flooded conditions was also duplicated by subjecting the selections to flood
conditions artificially and eliminating tile unsuitable types. The selection work
in certain rices has resulted in a few improved strains which show promise of
being better both in quality and yield than some of the present standard varieties.
Over fifty rice varieties imported from outside the province were under observa-
tion for determining their suitability to the Bihar conditions. A study of the
root-systems of rice under different conditions of soil has shown the compara-
tively better developed root-system in awcm as compared with (tun rices, and
that the root-system is best developed in clayey soils, the mixture of sand in it
inhibiting such development. The investigation on the factors governing
44 Qu&lity of fineness ” in rice has shown that the weight of grain per unit length,

iZ£h\?tT~ZnZ ia a much more reliable index than ordinary SIu ratioa -
Several cultural experiments were continued. Trials on spacing and number of
seedlings per hole in transplanted lice showed that it is more economical to
transplant 9" apart with only two or three seedlings to the hole. Dibbling of
seed was also found to be superior to broadcasting. The practice of dewatering
the field for about a fortnight at a certain stage of the crop again failed to show
any advantage over the normal irrigation practice. In the manurial trials,
Ammophos and ammonium sulphate were both equally good as fertilisers and
definitely better than sodium nitrate for South Bihar conditions, and superphos-
phate was not of any value. Manuring of seed-bed did not show any beneficial
e||ect on the subsequent growth and yield of the crop, and it appears that the
best time of applying artificial manures to rice is about two weeks after trans-
planting.

NOTE.

185

On the physiological side, studies of the mineral and water requirements of
the rice plant have been in progress. Ammonium salts appeared to be much
more beneficial than nitrate salts. Ho water-requirements of the crop, there
appeared to be a good deal of variation within each group of early, medium and
late varieties. There is also a well-marked period of high water-requirement
which starts about two to three weeks before flowering and continues right up
to the flowering time after which it begins to decline gradually. Studies on
salt-tolerance indicated the possibility of gradually educating varieties to tolerate
salinity. Desiccating agents like calcium chloride or sulphuric acid were found
to help the seed in retaining its viability for long periods, up to twenty-six
months. A study of the F a generation of some crosses indicated great complex-
ity in the inheritance of characters, both morphological and agricultural, and the
work is being continued.

BURMA claims on an average of the last three years 15.5 per cent, of the
total area and 17.5 per cent, of the total production of India. The area and
production during the year were 12,494,000 acres and 5,018,000 tons respectively.
Unlike other major provinces, the production during the year was slightly above
normal and about ten per cent, more than in the previous year. Although
Burma is responsible for eighty-six per cent, of the total export of rice from
India, the quantity exported during the year declined to 2,905,000 tons from
3,599,000 tons in 1934-35. Since the rice industry in the province is dependent
on her retaining her foreign market, attempts have been mainly devoted to the
production of rices to compete with the high-grade American and Spanish rices
in the United Kingdom and Canada. In addition to two improved Emata rices,
two Ngasein types have emerged successfully from tests conducted at eleven cen-
tres. These rices have been approved as suitable for both Western and Eastern
markets and seed is now being grown for commercial milling and trial shipment.
15,408,717 lbs. of improved seed was distributed during the year. The breeding
work at the Central Station consisted of the study of 180 hybrid cultures of
crosses betweeu local strains and local strains, and between local strains and
exotic varieties to evolve high-yielding types with big, bold and translucent
grain suitable for the export market. A large number of exotic .varieties was
also studied but most of these did not prove suitable for Burma conditions except
two from Siam. Under genotical studies, the inheritance of sterility proved
complicated and no connection was established between sterility and pollen
abortion. The inheritance of grain-size was of the usual multiple-factor type,
and grain shattering was found to be dominant over non-shattering. Under
manorial trials the experiment with a mixture of ammonium sulphate and sodium
nitrate has definitely proved that ammoniacal nitrogen is to be preferred for
rice.

Investigations on the photoperiodism in rice conducted at Mandalay by the
Economic Botanist have shown that the influence of the length of day profound*
ly affects the time of flowering. By artificially shortening the day a rice variety

186 * AGBicm/rmuL journo of British gviana. [IX, 3,

can be induoed to flower in forty days from sowing which would normally
require 135 days from sowing. There was, however, much sterility when
flowering occurred during the hot day season (April).

MADRAS. — This province contributed about 13.5 per cent, of the area and
to about 18.1 per cent, of the production of the total Indian crop. The reported
area for the year was 10,478,000 acres and the production 4,880,000 tons.
Nearly forty improved strains have been evolved suited to the varied conditions
of rice-growing obtaining in the province and the area under them is rapidly in-
creasing. Progress in the spread of strains was marked. Amount of seed sold to
cultivators was 2,479 tons. Seed-farms under departmental supervision and
through agricultural co-operative societies were arranged. Total area under
different improved strains of rice including natural spread was estimated to be
1,063,299 acres. Most of the fundamental work on rice is carried on at Coim-
batore but the district sub-stations deal mainly with simple selection work
in looal varieties and also conduct agronomic experiments suited to the
local eonditions. Six strains from two stations are being released for general
distribution to cultivators. Two strains from Coimbatore are of hybrid origin
combining valuable economic characters. Under cultural experiments work
at Coimbatore has shown that dibbling the seed in lines in puddle is just as good
as transplanting. Manurial trials gave tbo following results : Phosphatic
manures, in whatever form, had no response. At one station green manures
were better than mineral fertilizers applied to give the same amount of nitrogen.
At another station applications of nitrogenous fertilisers over a dressing of green
leaves gave definite increases in yield and the increase is progressive with high-
er doses of leaf application from two to ten thousand lbs. per acre and there is
a definite residual effect with the heavier doses. Irrigation experiments at
Coimbatore and Maruteru showed that in the former place a rice crop (August
to January) consumes seventy-eight acre-inches with a duty of about fifty and
that in the latter, the crop (June tc November) consumes fifty-four inches with
a duty of about seventy. Under fundamental studies carried on in
Coimbatore, the inheritance and linkage relationship of some of the morpholog-
ical characters have been worked out. The cytogenetic study of a large num-
ber of mutations isolated from the X-rayed material and polyploids was in
progress and is expected to be of considerable help in determining linkage
groups and the basic number of chromosomes in rice. Histological studies
showed that the coarse and coloured rices have thicker bran layere than the
fine and white rices. In connection with the marketing survey, a simple
laboratory method for cooking test was designed. Two hundred and seventy-
five samples of paddy and rice were analysed and cooking values determined
for forty samples of rice.

THE UNITED PROVINCES contribute 7.8 per cent, in area and 6.7 per cent.
i% production of the total crop in India. The area and the production were
6,643,000 acres and 1,983,000 tons respectively. The total quanity of seed
distributed during the year was 993,594 lbs. The research work is carried op

NOTH.

187

at Nagina. There were fifty-three varieties comprising indigenous and exotic
ones grown as single plant cnltnres. Over a thousand cultures from hybrids
were under study. The several manorial and cultural trials were repeated
during the year. The one important observation made in the several manurial
trials was that there was no difference among the treatments and none of them
did better than the control. Interploughing of the broadcast crop one month
after sowing failed to give any effect. An experiment with different quantities
of water, forty, sixty and eighty aore-inches showed no differences among them,
indicating that forty inches was quite enough. Studies on germination and
viability of rice seed showed that in early and medium ripening types the
panicles might be harvested twenty days after their emergence without affect-
ing the viability of the seed adversely. Hulling trials showed a correlation
between fineness of grain and breaking percentage. The fine-grained types
gave a higher percentage of broken grains than bold fine, medium fine and short
and round types. Re breakage during milling, crude parboiling of paddy was
superior to “dry” hulling. Though storage improved the hulling properties, the
hulling quality did not differ betwoen transplanted and broadcast rice.

THE CENTRAL PROVINCES AND BERAR contribute 6.9 per cent, in
area and 5.8 per cent, of India’s total production on an average of three years. The
area and production were 5,665,000 acres and 1,484,000 tons respectively. The total
quantity of rice distributed as seed during 1936 was 12,966,250 lbs. Research
work is carried on at Raipur and special emphasis is being laid on biochemical
problems. Results of chemical analysis have shown that a high percentage of total
phosphoric acid in the soil does not necessarily lead to a high yield in rice and
that there appears to be an inverse relationship between the lime-content of the
soils of a particular tract and the yields of rice obtained. Determinations of
soil-acidity have shown that in the case of most of the soils examined, the
acidity increases with depth and high yields of fine varieties of rice can
be obtained only from neutral or slightly acidic soils. Most of the soils
examined showed a lack of humus, its percentage being highest within
the top six inches. The humus content did not show any relationship
to the carbon-nitrogen ratio, which varied widely with different soil groups
and was lower at a depth of six' to twelve inches than in the top six
inches of the soil. The existing varieties of rice grouped according to their
times of ripening and quality were tested for yield and 168 out of 803 have
been retained for further trial. The hybridisation work in progress has got a
double object in view, namely, securing heavy-yielding types, and types with
deeply pigmented morphological parts as leaf-sheath, auricle, etc., to
distinguish them easily from wild rice. Experiments with nitrogenous and
phosphatic manures either singly or in combination showed that there was no
response for nitrogen even up to forty pounds per acre and the response to
phosphoric acid did not vary for applications of twenty to forty pounds per acre.
Comparison of Nicifos with ammonium sulphate showed that the former had a
residual effect while the latter had not. Varying doses of Nicifos from fifty
to three hundred pounds per acre all gave significantly higher yields than the

1§5 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 3.

no-mannre plot and the higher doses left a greater residnal effect than the
smaller doses. The caltnral experiment with broadoasted and subsequently
oross-plonghed, drilling, etc., showed that on sandy loam land, in all varieties
tried, transplanting was better than broadcast-sowing and drilling.

A -ISAM contributed to the total rice area and rice production in India
6.1 an i 5.4 per cent, respectively on a three years’ average. The acreage and
production were 5,292,000 acres and 1,610,000 tons respectively. The research
work is carried on at Karimganj and Titabar. A certain number of strains,
selections and cross progenies suited to conditions have already been evolved
and distributed, such work forming one of the important activities of the
department. Work with varietal, cultural and manurial trials besides breeding
and selection were carried out. Under the scheme of analysing market
samples of paddies and rices to fix grade standards, 134 samples were examined.
Cooking tests were also conducted with twenty-two samples of rice. Problems
relating to deep water rices are peculiar and entail special equipment to study
them properly. Cultural experiments with time of sowing and seed-rate and
complex experiments involving time of planting, spacing, age and number of
seedlings per hole in certain rices have been laid down and preliminary
results obtained.

BOMBAY contributes on an average of the last three years 2.4 per cent, in
area (1,832,000 acres in 1935-36) and 3.1 per cent, in production (740,000 tons
in 1935-36) to the total rice crop in India. Bombay imports considerable
quantities of rice from Burma and other proviuces and re-exports portions of
it to Africa, Persian Gulf, etc. During 1936, 30,000 lb. of seed was distributed
to registered seed-growers. The area under the improved strains is estimated
to be 13,524 acres. Breeding work is carried on.

SIND contributed about 1.5 per cent, of India’s production out of a little
over a million acres. 497,822 lb. of seed was made available to cultivators.
Breeding work is carried on which has resulted in three improved strains. The
improved hybrid strain obtained by crossing Kangni 27 with Kolamba 184 and
which has been named 4 Silver Jubilee ’ rice was tried at several places on a
large scale and has given satisfactory results, the yield per acre going up to
3,400 lb. A large number of exotic varieties has been tried but most of them
are not promising. Experiments with duty of water showed that a normal
crop with fairly good yields can be raised in a normal season with thirty duty,
the crop consuming about forty-five to fifty-five acre-inches.

Rice is a minor crop in the PUNJAB and oocupies less than a million acres.
Breeding work is carried on and a total supply of 355,962 lbs. of seed of
improved varieties was distributed. A large number of local varieties (sixty-
four) has been tested at the Btation and variety 246 Suffaida continues to be
oufttanding. Under cultural trials transplanting is found to be better than
broadcasting and seedlings of ages above si* weeks were better than younger
Seedlings below five weeks,

NOTE.

189

The HTDERABAD STATE contain* over a million acre* under rice in
1935*36, bat produces only about 336,000 tons of rice. Selection work has
given two early types. Other more promising types are under test. The area
under improved strains during the year is 1,765 acres.

The area under rice in MYSORE during the year was 741,000 acres and
the estimated production 222,000 tons. Breeding work is carried on. Some of
the new Mysore selections are very promising and district trials have created a
demand for them by the cultivators. During the year 65,000 lb. of padi seed
was made available to cultivators and the area under improved strains in the
State is estimated to be 53,000 acres.

The area under rice in the TRAVANCORE STATE is small and nearly fifty
per cent, of the requirements has to be met by imports. Side by side attempts
are in progress by the Agricultural Department to improve the yields in existing
areas by the spread of improved strains and by advocating better manuring
practices. During the year 6,88!) lb. of seed was sold. Certain manurial trials
in progress have shown that addition of bone-meal, fish guano or laurel cake
definitely increases the acre-yields.

COCHIN. — Rice is an important crop and though no regular breeding work
is done, simple selection has been attempted and one of the strains evolved is
becoming popular. Manurial trials in rice have shown the importance of
organic manures.

Breeding work on a small scale is being carried out atKARNAL station.
A preliminary experiment with four types of rice showed that transplanting
seedlings with regular spacings was better than the local practice in which no
regular space is maintained.

F.B.

NEWS.

The Director at Agriculture visited Berbiee tram September 14 to 17.

The Deputy Director of Agriculture visited Berbiee from August 22 to 26
and Essequibo from August 29 to September 3.

The Government Veterinary Surgeon visited Berbiee on several occasions in
an effort to control an outbreak of anthrax in that area.

Members of the Essequibo Central Rice Mill Committee including the
Director of Agriculture and Mr. H. D. Huggins visited Essequibo on July 8 in
order to make an inspection of the mills and to interview those connected with
the Essequibo rice industry.

Mr. James D. Gillespie, B.Sc., Agricultural Superintendent in this Depart-
ment. left the Colony on August 30, on six weeks' vacation leave from date of
arrival in the United Kingdom, prior to taking up his new post as Agricultural
Officer, Sierra Leone. He takes the best wishes of his colleagues with him in
his new sphere of activity.

With effect from September 12, 1938, inclusive, Miss N. Green, Class III
Clerk of this Department, has been seconded to the' General Register Office and
Miss S. Lord, Probationer of that office, has now joined the staff of the

Department of Agriculture.

Mr. H. Balkaran Singh, of the Sugar Experiment Station Laboratory, has
passed the Final Examination in Sugar Technology of The City and Guilds of
London Institute. Mr. Singh is to be congratulated on his success.

Mr. Hubert Parker, Manager of Government Rice Mills, Federated Malay
States, who has been detailed to investigate the possibility of the erection of a
Central Rice Mill in Essequibo, and generally to go into rice milling problems in
the Colony, arrived in British Guiana on September 19. Before leaving for
the districts, Mr. Parker is spending the first few days of his visit in George-
town studying matters connected with the industry.

Among the visitors to bihe Department was Mr. Herbert G. Ford, Sales
Representative of the U.S. Phosphorio Produots Corporation, Broadway, New
York.

A meeting of the Advisory Board of Agriculture was held on Wednesday,
August 10.

Efforts are being made to reawaken local interest in poultry and the Poultry
Association has been resuscitated. Meetings were held at the Head Office,
Department of Agriculture, on August 12 and 19 and September 5. Rules were
drafted and adopted and a President and other officers elected.

At a Village Chairmen’s Conference held on Tuesday, August 16, at La
Gringe, West Bank, Demerara, His Excellency the Governor attended and gave
an address. The Director of Agriculture was also present arid made a short
reference to the possibilities of a poultry industry in village areas.

PLANT AND SEED IMPORTATION.

Introductions by the Department of Agriculture for the period
J une — September, 1938.

Kami

Quahtity.

Whence Supplied

Economic,

Mango, 7 varieties

4 seeds each

Puerto Bieo Agrl. Experiment
Station.

Cauliflower (Maincrop Benares)

2 oz.

Sutton & Sons (Calcutta).

Dioscorea (data

tubers

Agrl, Dept., Dominioa,

Padi, 6 varieties

} oz. each

Orissa, India.

Padi, 5 varieties

i oz. each

Sflo Paulo, Brazil.

Guava, 3 varieties

1 oz.

Kirkee, India.

Peas, 14 varieties

i oz. each

Pnsa, India.

8 rgo, 2 varieties

i lb. each

U.S. Dept, of Agric., Wash-
ington, D.C.

Bananas, (Hawaiiau Cooking) 4
varieties

Buckers

Canal Zone Expt, Gardens.

Ornamental.

Early Flowering Sweet Pea •

2 pkts.

Sutton & Sons (Calcutta).

Nelunbium luteum

3 os.

Dept, of Agriculture, Jamaica.

Frangipanni, 3 varieties

cuttings

Dept of Agriculture, Barbados.

Alttonia sp.

1 pkt,

Dept, of Agriculture, Bermu-
da,

Ptrittropht tpteiota

do.

’

Dept, of Agriculture, Bermu-
da.

METEOROLOGICAL DATA— AERIL TO -JUNE, 1938.

Recording Stations k
Months.

Botanic Gardens.

April

May

NUMBER Of DAYS Of RAIN

5 " li

S s g-S" 55
5 «g «8

Totals

19 8

Air Temperature
and Humidity.

44 7 844 76-3 80-3 82-0
44 2 84 9 76-2 S0 5j 84-8
3-92 84-5 75-3 79-9 84.3

72 12.21

Means

84.fi 75.9 80-2 83-7

Berbice Gardens.

8-84 (5 9 3

4 2 22'
1 1 26

864 75.1 80. 7 1 82-9
I 87.7 75.5 81-6 82-9
i 87-2 75-1 81 4 1 80.9

Totals

39 60 20

Means

87.1 75-2 814 82-2

Onderneeming.

April

May

Totals

11.21 1
14-80 3

38-59 6

84-9 74.5 79-7 90.9
854 744 79.6 92.4
81-6 72-7 78-6 934

Means

84-9 73-8 79-3 924

Hosororo,

North West District I

Lpril
lay
une 4

... 10-91 7

... 12-31 4

.. 13-80 3

84-8 70-5 77-6 864
85.5 71 .6 78-5 88-6
85.7 714 784 87-5

Totals

37-02 14

CURRENT Hfc!<3ES PRODfCE

Front The Commercial Review Journal, of the Georgetown Chamber
of Commerce , Vol. XXI, No, 8, Wednesday 31st August, 1938.

SUGAR,

Per 1QO lb; net 3 lb. per Bag allowed for tare

Dark Crystals for Local Consumiption 13.30

Tellow Crystals do. ' do. .'... $4.00

White Crystals $4.75

.Molasses Sugar none offering.

Above Prices include Excise Tax of 90c.

RUM.

Imperial Gallon. Cask included.

Coloured, in Puncheons — 40 to 42T O.P:..(for export). ..60c.; Hhds.52c., Barrels 77c*

White, in Hogsheads— 40 to 45 O.P...(for local consumption) 45 to 55c.

MOLASSES.

Per Imperial Gallon. Naked.

Yellow (firsts) 10c.

Yellow .(seconds) .....5$c.

RICE.

Rice per Bag of 180 lb. gross. Brown Super $5.00 scarcity ; Extra No. 1,

$4.25— $4.50 j White, None available. Lower Grades $3.35 — $3.65 as to quality
Padi per Bag of 143 lb. gross, $1.20 — $1.50 as to quality.

GENERAL.

Gold, Raw, average per oz. $26 to $27.

Diamonds, — pro rata as to quality ...average per carat $10 to $11.

Timber, Greenheart, (Lower grade measurements). ..40c. to 60c. per c. ft. ;

for export 72c. to $1.00 perc. ft.

do. Railroad Sleepers — (Mora) $1 .68 each.

Greenheart Lumber $70 to $80 per 1,000 feet.

Crabwood Lumber $60 to $75 per 1,000 feet.

Shingles, Wallaba, 4 x 20 and 5 x 22 inches $4.50 to $6.00 per M.

Charcoal, Capped for shipment., -.. 72c. to 85c. per bag.

Firewood $2.50 per ton.

Cooonuts... Selects, $9.00, culls $6.00 per M... Copra $2.50 per 100 lbs. prime Copra.

Balata ..Venezuelan, none. Local Sheet... 36c. to 38c. per lb.

Cocoa 19c. to 19ic. „ „

Coffee 6c. te 6ic. „ „

N.B. — Duty Payable on value at time of Importation and rate of exchange on day of
arrival.

THE CERTAINTY
OF DAWN.

In quiet confidence-*
and in the adherence
to sound business prin-
ciples— lies the way to
true success. The Royal
Bank offers to legiti-
mate enterprise the
security and prestige
which sixty-six years of
experience have built
up. • • • *

Tfl E

ROYAL BANK

OF CANADA

llllllllllllBUIfIlillllllltli|lllliaillllIltlUlllljllflltllItlIfltllll 1 llltlttltl«naillillUllll!llltlMlll«Ill!tllllUlillt!Slt 8 III 218 lt 8 !||llBliailll>lUllllUlltlUI)IIIIIUai!IUatlllli

ELECTRIC MOTORS |

ARB IN A CLASS BY THEMSELVES FOR DRIVING—

DRAINAGE PUMPS

and other Machinery connected with Agriculture.

■ - ■ ♦ —

The Benertri Electric Ctipaiy, Ltd.

Headqmsrtere for Electrical Supplier.

VoL IX, No. 4 *

December, 1938.

The

Agricultural Journal

British Guiana

PUBLISHED BY

THE DEPARTMENT OF AGRICULTURE,

GEORGETOWN, B1UTI8H GUIANA

Price

$d,

Mttftfft&itf of iseittcotTME,

AWHNISTRATfON

Director of Agriculture ...

Deputy Director

...

Clerical Staff.

Prof. The Hoau J. Sydney Dash,
B.Sc. (Agnc.)

(vacant)

E. M. Peterkin (acting)

Senior Clerk

•••

J. F. Irving, M.C.

Registrar of Banks

... «

W. G. Delph (on leave)

A. A* Thorne (acting)

Class III Clerks

.. *

0. A. Lsshley (acting)

Miss D. M. Terrill

Probationers

.. .

/ Miss M. Cbeong

I P. 0. Jackson
j 8iA, Adams
j Miss S. Lord
^ Miss R. Delph

Librarian ... ...

Miss V. Chan-Choong

RESEARCH BRANCH.

Botany and Plant Pathology

Botanist — Plant Pathologist and Superintend-
ent, Botanic Gardens :

E. B. Martyn, B.A., A.I.C.T.A.

Technical Assistant :

N. Persaud

Chemistry

Chemist :

D. W. Duthie, M.A , B.Sc., Ph.D., F.I.C.
Assistant Chemist :

C. L. C. Bourne

Entomology

Entomologist ;

L. D. Cleare, F.R.Ent.S.

Technical Assistant :

C» Williams

Rich

Assistant Plant Breeder :

P. A. ChanChoong, B.Sc., A.I.C.T.A.

Sugar

(In co-operation with the Sugar Produoers)
Sugar Agronomist and Plant Breeder :

c. H. B. WillianifeJfcA*, A.I.C.T.A., Dip,
Agr. (on leave)

Laboratory Assistants :

H. B. Singh*

A, V, Wan*Ping, Dip. Agr.
matisHcal Clerk t
J* B. Bourne

LIVESTOCK BRANCH

Veterinary Surgeon:

£* O.B.E., M.R.C/V.S. (on leave)

H A Fraser, B.V. Sc (acting)

FIELD BRANCH

Agricultural Superintendents :

Berbice— (Vacant)

Demerara, Bast — E. M. Peterkin
Demerara, East Bank— H. D Huggins,
M.Sc., Dip. Agr.

Demerara. West — E. G. Benson, B.Sc,,
A.I.C.T.A., Dip. Agr.
Essequibo— A. A. Abraham
Assistant Agricultural Superintendent:

Betbioe — E. M. Morgan
Agricultural Instructors ;

Botanic Gardens— H. A. Cole

(C. 0. Dowding, F.L.S.,
Demerara, East— ■< F.R.HLS.

vG. L. Leitch (acting)
Demerara, East Bank — I. Dewar (acting)
Essequibo— A. W. Sears
North West District— L. B. McKinnon
Berbice— O. F. Jt Clmraman, Dip. Agr.
Agricultural Assistants;.

Demerara, East— J: Ihdrobehacry
Berbice— H. B. France •

Sugar

Field Manager (Central Static*)
C, Cameron
Field Assistants i
L. A. Forte

B. A. McArthur %

MtetEOiiOtOGiCAL BfeA^Ctt

technical Assistant :

D. D. Blackman

Meteorological Assistant :

J. E. Isaacs

ftJCE GRAttfoG 'hRANCh

Grading Inspector:

H. E. H. Gadd (on leave)

H. D. Hoggins (acting)

Technical Assistants ;

W. A, Boveii (acting)

R. R. Ross

ADVISORY BOARD OF AGRICULTURE

Director of Agriculture, Chairman, ex officio.

Deputy Director of Agriculture, Vice-Chairman, ex officio.

Hon. 1 Peer Bacchus ... ... ... \

Hon. R. E. Brassington ... ... ... I

Hon. J W. Jackson ... ... ... [

Hon. F. J. Seaford, o.b.e ... ... ... > Members

Mr. S. Andries ... ... ... ... I

„ R. B. Hunter ... ... ... I

,. W. H. Richards ... ... ... /

SUGAR EXPERIMENT STATIONS COMMITTEE.

Director of Agriculture, Chairman, ex-officio.
Hon. M. B (t. Austin, o.b.e.

Mr. G. M, Eccles
„ J. C. Gibson
„ A. Murison
„ R. E. Rhodes
„ J. Bee

Georgetown
Pln^filairmont
Pin. Port Mourant
Pin. Uitvlugt
Pin. Diamond
Pin. Albion

N Representinj
the Sugar
Industry
which main*
tains the
/ Stations

CO-OPERATIVE CREDIT BANKS’ BOARD.

Director of Agriculture, Chairman, ex-officto.

Hon. J. W. Jackson
Rev. A. E. Dyett ...

Mr. C. Farnum ...

„ J. L. Wills ...

Members

DISTRICT AGRICULTURAL COMMITTEES

EAST DEMERARA

Director of Agriculture, Chairman
District Commissioner

Deputy Director of Agriculture
Hon. J. I. de Aguiar

...

Hon. E. M. Walcott

Mr. S. Andries ...

» •

... > Members

„ M. Ghaui

...

... [

„ W. H. Richards

...

„ J.E. Wills ...

...

WEST DEMERARA

Director of Agriculture, Chairman
District Commissioner
Deputy Director of Agriculture
Hon. J. W. Jackson
Dr. the Hon. J. B. Singh ...

Mr. R. P. Carryl

,% J. C. DaSilva ... ... ... ►

„ R. B. Hunter
„ A. Murison ...

„ W, Ramdeholl
„ A. Baym&n ...

Members

contents.

(Vol. IX, NO. 4.)

EDITORIAL —

ORIGINAL ARTICLES.

Malaria in British Guiana, . .

Part III. ... ... O . GiffhW , M.D , (//,), M.R.C.P. ( Bond .),

D.TJd.&H.(Eng.) ...

The Georgetown Botanic

Garden ... ... E. B. Uartyn , B.A., -4.J.G.7L4.

A Water Rat (Hoplochilus
sciureus berbicenais Mor-
rison- Scott) Damaging
Sugar-Cane in British

Guiana ... ... L. D. Cleave , F.R<Ent.S.

197

207

217

A Short History of the
Rupununi Savannahs with
Special Reference to the

Livestock Industry ..* EL. E. Turner ... ... 230

Damage Caused to Rum
Puncheons by Boring

Beetles ... ... L. D . Cleare , F.U.Enf.S. ... 237

A Summary of Agricultural
Legislation in British

Guiana ... ... ... ... ... ... 240

REVIEWS.

Cacao and Witch Broom
Disease {Marasmius perni-
ctosus ) of South America

by F. J. Pound ... ... ... ... ... 263

The Principles of Cane
Sugar Manufacture by J.

G. Davies ... ... ... ... ... ... 264

NEWS ... ... ... ... - ... 265

LEGISLATION ... ... ... ... ... 267

PLANT AND SEED IMPORTATION ... ... ... 268

METEOROLOGICAL DATA ... ... ... ... 269

CURRENT PRICES OF COLONIAL PRODUCE ... ... 270

« ILLUSTRATIONS

Facing Page

Plate I. — Figs. 1 & 2 — Typical breeding sites of A. davlitigi

in the interior. ... ... * ... 198

PLVTE II. — Fig. 3 — Typical breeding site of A. darluigi in

# the interior. Rain water swamps in the

mid-Demerara. ... ... ... 199

„ — Fig. 4 — Abandoned factory sites, with bush covered
foundation pits and obsolete canakj, form
ideal breeding sites for A. ddrlingi « Ml 199

Contents— (Continued ) .

Facing Page

late III. — Fig. 5 — Plan of irrigation canals, drains and'

drainage trenches in a group of four sugar

cane fields. ... ... ... 200

LATE IY. — Figs. 6 & 7— Typical breeding sites of A. darhngi

on the coast. ... ... ... 201

’late V. — Fig. 8— Flooded fields lying fallow, when covered

with floating and vertical vegetation and
favourably exposed, may be productive
sources of A . darlingi . ... ... 202

„ „ — Fig. 9 — Rice fields situated beyond the salt coastal

front lands, and sheltered by trees and
scrub are favourite breeding sites of
A . darhngi. ... ... ... 202

Plate VI. — Fig. 10 — Open, windswept rice fields in the salt

coast front lands are favourite breeding
* sites of A . tarsimaculains , but only very

exceptionally harbour A . darhngi . ... 203

Plate VII. — Fig. 1 — The Entrance Qates and Lodge today ... 208

Plate VIII.— Fig. 2— The Main Avefnue and “Flower Garden” ... 209

Plate IX. — Fig. 3— The “ Oronoque Avenue” now the Cen-
tral Avenue through the Park Lands. ... 210

Plate X.— Fig. 4 — The Band Stand and “Flower Garden.” ... 211

Plate XI, — Fig. 5 — The Iron Bridge over No. 2 Lake ... ... 212

Plate XII. — Fig. 6 — Jenman’s House and Herbarium, now the

residence of the Director of Agriculture. ... 213

Plate XIII. — Fig. 7 — Lotus Lilies in a Lake in the Park Lands. ... 214

Plate XIV. — Fig. 1 — Nest of Uoplochilus sciureus bcrbicensis

M-S, made of cane leaves ... ... 218

„ „ —Fig. 2 — Estate dam showing Razor Grass which

served as cover for rats. ... ... 218

Plate XV.— Fig, 3 — Damage to cane stalks by Hoplochtlus

Bciureus berbicemis M-S. ... ... 219

„ — Fig. 4 — Damage to tops of cane shoots by Hoplo -

chilus sciurem berbiccnsta M-S. ... ... 219

IPlatb XVI, — Fig. 5 — Ratcatchers with dogs working over sav-
annah recently empowered and ploughed ... 226

,, — Fig. 6 — Ratcatchers with their “hunting dogs”

* working in taller canes ... ... ... 226

Plate XVII. — Fig. 1 — The effect oh Pasture of overstocking ... 222

„ * —Fig. 2— Cir«rt?red Zebu Hereford Heifir. ... ... 222

Plate XVI !l!— Fig. 3— A Herd crosslag tho Sittronuni River ... 223

—Fig, 4— Driving a Mixed $Ierd ... ... ... 223

The

Agridtvsl Journal of British Guiana.

Member, 1938*

EDITORIAL.

ROYAL COMMISSIONS-PAST AND PRESENT.

When the Royal Commission arrive here early next year it will be just over
42 years since the last Royal Commission was in the Colony, and comparison of
the state of affairs then and now gives food for thought. Since the last Com-
mission the wheel has turned a full cycle, tor from the state of depression which
brought about the arrival of the first Commission, the Sugar Industry, ever the
mainspring of the colonies, has risen to prosperity during the boom years of the
war, and dropped back again to necessitate the Sugar Commission of 1929. Des-
pite the advances made by the industry both in field and factory, the last nine
years have been difficult ones and, economically, the planters today are again faced
with a position similar to that obtaining in 1896, but it is to be hoped that the
wheel has passed dead contre and that its further movement will be toward
better times.

The Commission appointed in 1896 consisted of General Sir Henry Norman
as chairman together with Sir Edward Grey, Sir David Barbour and Mr. (after-
wards Sir) Daniel Morris as Agricultural Adviser. Its Secretary, Mr. Olivier,
was destined to re-cover the ground when, as Lord Olivier, he and Mr. Semple
constituted the Sugar Commission of 1929. The ’96 Commission came into
being as the result of intense depression b: ought about in the sugar industry by
the competition from Beet sugar produced in Europe under a system of bounties.
An appeal for assistance from the Home Government had been made by the
planters and all those whose fortunes were bound- up with the industry. British
Guiana was one of the colonies most seriously endangered by the existing state
of affairs, and it was to this Colony that the Commission came ficst on leaving
England, passing on to the West Indian islands and ending in Jamaica, where
the effects of the depression were less serious than elsewhere, owing to the in-
creasing number of peasant proprietors, and the possibility of substituting other
crops for sugar, notably coffee, and also bananas, which were already coming
into prpmincnce.

The present Commission has begun its enquiries from a different
point in more ways than one. In the first place, its primary object
is to investigate the conditions of labour in the colonies visited, in
other words, this time the difficulties of the employee* rather than
the employer^ formed the basis of its appointment which was made,

196

AGRICULTURAL JOUBSAL Of BRITISH GUIAHA*

Ut, t

not after an appeal from the colonies, but as the result of discussions In
Parliament after the labour unrest in Jamaica had followed closely upon the
serious disorders in Trinidad last summer. The Commission this time has visited
Jamaica first and will end with the southern colonies, its scope also Including
British Honduras, whioh was not visited before.

'We may now consider more closely ttie two Commissions in their relation
to British Guiana. When the Norman Commission came to the Colony they
were largely concerned with the possibilities, if any, of finding a substitute for
sugar, which then, as now, formed 70 per cent, of the Colony’s total exports. At
that time, gold had recently come into prominence in British Guiana, and it was
hoped that it would render considerable help towards swelling the Colony’s
depleted revenue. Mr. Morris had painted for the members of the Commission a
most glowing account of the agricultural possibilities of the interior, which they
would not allow to be damped to too great an extent by the somewhat conflicting
evidence of the Director of Science and Agriculture, Sir John Harrison.

Crops, the cultivation of which it was suggested at the beginning of the
century could well be extended, included coffee, fruit and rice. The viscissitndes
which these have undergone in the ensuing years need not be recapitulated —
suffice it to^ state that the only crop which has been able eventually to establish
itself in a position of importance, though still very far behind sugar, is rice,
which now constitutes approximately 8 per cent, of the Colony’s total exports.
The answer however, to the query whether the Colony is dependent on a single
export crop to a dangerous extent must still be in the affirmative. The position
however, is slightly better than it was in 1896 when, if gold were excluded, sugar
formed 94$ per cent, of the total exports, and if marketing problems can be
solved and milling put upon a sounder basis, rice may be able to exert an ever
growing influence on the Colony’s budget.

But the present Commission is largely ooncerned with labour and conditions
affecting the labourer ; it includes Sir Walter Citrine and two women members
with considerable experience of social and health questions. All classes will be
given a chance to disclose their grievances, and by the time the Commission
reach Georgetown the information and experience that they have gained in the
early part of their journeyings will enable them to see these in perspective and
judge them on their merits. There have been no labour disturbances in this
Colony comparable to the rioting and disorder which occured in Trinidad and
Jamaica, but there have been a number of strikes throughout the past eight
months and a continual undercurrent of unrest, which has hampered the routine
of the sugar estates and disturbed the current of the lives of the great majority
of labourers and peasantry, whether discontented or not.

We welcome the arrival of the Commission and hope that when the basic
problems have been discussed with its personnel, and we have been enabled to
benefit by their deliberations, the Colony with its strangely heterogeneous
population will unite to further the turn of the wheel towards prosperity.

MALARIA IN BRITISH GUIANA.

Paw III. BREEDING HABITS OF A. darlingi. NATURAL FACTORS
WHICH LIMIT THE DISTRIBUTION OF THIS SPECIES AND OF

MALARIA.

G. GIGLIOLI, M.p. (It.), m.B.C.p. (Loud.), d.t.jc. & h. (Eng.)

Medical Adviser to the Sugar Estates of British Guiana,

We have established in the previous sections that A. darlingi is the sole
malarial vector of practical importance out of the three local common Anopheles;
we will now proceed to study the breeding habits of this species as such know
ledge is essential for the carrying out of an intelligent control policy.

Breeding Habits on A. darlingi in the Interior:

We have seen that A darlingi is the main malarial vector throughout
equatorial South America ; it is eminently an inhabitant of the vast inland forest
districts of this region.

Our observations, in this Colony, have been carried out on the mid and
upper Demerara, mid-Essequebo and Potaro Rivers. These districts offer good
examples of the various conditions which exist in the interior, as regards surface
water regime.

The Demerara River is subject to tidal variations for a distance of close on
100 miles from its mouth, where the first rapids are found. The river banks are
formed by low, alluvial mud fiats entirely covered by forest. The first sand
dunes, which are also covered with dense vegetation, rise 25 miles from the sea
and extend some 50 or 60 miles, when higher hills and rock formations make
their appearance. The mud flats present a somewhat higher bank or dam
bordering the river ; on this all the settlements are placed.

The flats tend to get lower as one proceeds from the river bank towards the
foot of the sand dunes, where extensive forest swamps are usually to be found.
Some of these swamps are subject to regular tidal invasion from the river ; their
waters are limpid, soft, dark brown in colour, and very acid (pH 4 to 5). They
are very poor in algae and other vegetation ; the naked, black submerged trunks
and limbs (TacobasJ have a characteristic charred appearance; planktonic life
also appears to be remarkably scarce,

198

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[IX, 4.

Acid, peaty waters of this description form a very large proportion of all
sarfaoe waters in the interior ; they appear to be unsuitable for the breeding of
A. darlingi as we hare never found them harbouring larvae of this species.

In some localities, white water springs exist at the foot of the sand hills ;
in the absence of direct communication with the river or with brown water
creeks, clear white water swamps tire formed ; such waters are only slightly acid,
and sometimes neutral in reaction (pH 6 to 7). Vegetation of all kinds is here
more abundant, and green algae are frequently noted, covering the submerged
logs. These white water swamps are favourite breeding sites of A. darlingi ;
being permanent they are particularly dangerous, and in their neighbourhood we
have found this species ail the year around (Figs. 1 & 2).

During the heavy rains, from May to July, extensive rain water swamps
collect in low places not subject to tidal invasion; these too form suitable breed-
ing sites for A. darlingi . Finding the larvae is a labourioqs task as their disper-
sion is very great. When the dry weather sets in, most of these rain water
collections disappear ; in others the characters of the water gradually change
through prolonged contact with decaying vegetation, a'nd they become aoid and

unproductive of Anopheles (Fig. 3).

In conclusion :

The acid dark waters of the tidal rivers and of the black forest creeks
and swamps, tidal or otherwise, are permanently unsuitable
for the breeding of A. darlingi.

Rain water collections and* swamps are suitable ; they give rise to only
temporary or seasonal breeding.

White water seepage swamps and creeks are dangerous and more or
less permanent and productive sources of A. darlingi.

Besides the physio-chemical characteristics of the waters, other factors
influence the breeding of A. darlingi.

Fairly large volumes of water are preferred; a fair combination of shade and
direct sunlight appears to give optimum conditions ; a certain amount of cover in
the form of vertical vegetation and floatage are required.

The seasonal factor is also important ; breeding is active during the warm
weather following the spring and early summer rains; it is scarcely affected by
the autumn rains. These, in fact, actually appear to have an unfavourable bear-
ing on the survival of the adult Anopheles from one season to the other;
conversely, failure of the November-December rains is often a prelude to an
unusual Anopheline and malaria prevalence in the following summer.

Min-made breeding sites are of little moment along the tidal rivers. The
Berbice, Pomeroon and Moruka rivers all present similar characters to those we
have described on the Demerara.

Plate I.

Figs* 1 4k 2* — Typical breeding sites of A. darlwqi in the interior : white water seepage swamps on
the mid-Demerara Biver. Though apparently completely covered by luxuriant
vegetation, the water is exposed to a certain amount or direct sunlight.

Plate II.

Fig. 4. —Abandoned factory sites, with bush covered foundation pits and obsolete canals, form ideal
breeding sites for A. darlmgi .

malaria is British ggiaka.

190

The mid-Essequebo river is subject to regular, periodic floods; the poise of
these floods is regulated by the rainfall over large tracts of land in the far
interior* In these continental areas the distribution of the rainfall is much more
characteristic and constant than on the coast : there is a single and well defined
rainy season, from May to August.

These Essequebo floods, therefore, as the inland rainfall which causes them,
are regularly periodical, reaching their peak in the month of August. During
the floods hundreds of square miles of forest are submerged over the 600 mile
course of this great river.

The waters of the Essequebo are of a very light brown colour, and their
reaction is only slightly on the acid side. These physio-chemical features vary
considerably along the course of the river according to the characteristics of the
waters of the larger tributaries. The Potaro, for instance, brings to the Essequebo
a large volume of dark brown acid water, and the two currents keep separate for
some miles after their confluence.

The mid-Essequebo valley is flooded during the local early summer rains.
These local rains, conversely to what occurs on the tidal rivers, can have little or
no importance as regards the breeding of Anopheles. We found at Rockstone and
Butakari that A. darling i made its appearance during and immediately after the
floods, when the falling river waters left behind extensive swamps presenting
favourable conditions for the breeding of this species. Here again the finding
of larvae is a difficult task owing to their wide dispersion.

At Rockstone A. darhng i is particularly abundant, as the small clearing,
surrounded by forest, offers those conditions of shelter, shade and sunshine which
we have already described.

This peculiar complex of conditions which prevail on the mid-Essequebo
causes the seasonal incidence of Anopheles and of Malaria to be remarkably
regular.

These are the reasons for which the epidemiology of Malaria differs pro-
foundly from one district of the interior to another : in 1926, for instance
Malaria prevailed in severe epidemic form throughout the Demerara and other
tidal river districts, yet Rockstone and Butukari on the Essequebo, less than 20
miles away, were in no way affected. All these districts experienced that year
the same abnormality in the distribution and abundance of rainfall ; but while
on the Demerara these rains caused the production of a very unusual amount of
suitable breeding sites at a particularly favourable season, on the Essequebo these
same ra^ns fell on a normally flooded valley, and the seasonal Anopheline and
malarial exacerbation followed its usual course, after the flood, quite uninfl uenced
by abnormal local meteorological conditions.

On the torrential flood rivers, like the Upper Demerara an<| the Potaro,
both of which have dark acid waters, the breeding of A. darlingi *is essentially
related to the rainfall. Where white water creeks and swamps occur permanent
favourable breeding sites are provided*

§66 J0tftSAl> O* BRITISH GUIANA. [Et, 4.

Ia the Potaro and other gold and diamond mining districts, man-made
breeding sites are of particular importance. Old gold pits filled with min water
and other artificial collections, as required for washing and sluicing for gold and
diamonds, may all be productive sources of A. darlingi in close proximity to the
miners’ camps.

Bodkin (1921) states to have found Anopheles breeding in discarded tins
and other containers in the Potaro district.

Both in that locality and elsewhere in the Colony, and over many years, we
have completely failed to substantiate this claim. We have never found A. dar-
ling i, nor A. tarsi maculatus, or A. albitarm either, breeding in containers of
any description ranging from rainwater vats to sardine tins and coconut husks.

Accurate statistics as regards the topographical distribution of A. darlingi

and of Malaria in relation to the distribution of these various types of Burface

waters in the interior are not available for the present. It is certain that the

incidence of Malaria varies very considerably from one locality to the other.

In our own experience, on the Demerara, swamps due to white water springs of

low acidity were constantly associated with a high Anopheline incidence and

with severe endemic Malaria.

Breeding Habits of A. darlingi on the Coast.

Surface water conditions on the CoaBt are varied and different from those of
the interior, owing mainly to the very low level of the land, and to its being
Settled and cultivated.

A very large porportion of the inhabited coastal belt lies below high tide
sea level. It is liable, therefore, to tidal flooding from the sea, and seasonal
flooding from higher lands farther inland during the rains. From such contin-
gencies, this area is protected by sea defences abd back dams. Drainage is
carried out by means of a very extensive net of trenches which empty themselves
into the sea, sometimes by gravity (during low tide only), more often through
powerful pumping stations.

In East and West Demerara efficient sea defences exist along the shore line.
Sea water infiltration is very small, being practically limited to leakage from the
sea sluices at high tide. In Western Berbioe and on the Corentyne, in particular,
vast tracks of the front lands are open to regular tidal invasion and salt water
finds its way for a distance of some miles inland.

Such tidal invasion, present and past, reflects itself in the salinity of the soils s
we find that on the East and West Coast of Demerara, there is only a narrow
strip of salt land more or less corresponding to the front pastures, which extend
for a depth of one mile from the sea wall at the most.

. As one proceeds towards the east the coastal salt land belt becomes progress-
ively wider. In Western Berbice, tidal waters in many places reach beyond the
railroad line, and salt soils are f onnd for a depth of two or more miles from the
Shone line. »

DUTCH LAY-OUT. ENGLISH LAY-OUT.

Pig. 5 » — Phil of irrigation canals, drains and drainage trenches in a group of four sugar cane fields The disposition
of the small drains within the fields varies and the two usual layouts, Dutch and English, are shown. A square mile of
land laid out as above, in 10 acre fields, would include 16 miles of irrigation canals ; 41 of drainage trenches and 45 miles

Plats IV.

* Flfs* 6 & 7« — Typical' breeding Bites of A. darliiwi on the coast. Irrigation canals, sheltered by
overhanging cane and covered w ith floating vegetation in which the larvae and pupae
find protection from the attacks of larvivorons fish.

MALAftU IS BHITISH O0IANA. SOi

On the Corentyne Court, salt marshes extend a long way inland and the soils
are xloh in soluble salt for a very considerable depth. The waters whieh collect,
dnringthe rains, on the extensive savannahs lying aback of plantations Rose Hall,
Albion, and Port Monrant, aS the dry weather sets in, tend to become too salt for
irrigation purposes. This occnrs 10 or more miles inland.

We find, in conclusion, that a very large proportion of the surface waters of
the coastal front lands are affected by tidal invasion or by contact with soilB
which are rich in soluble salts. The former are permanently brackish, (Coren-
tyne front land marshes) ; the latter tend to become brackish during dry weather,
by long contact and concentration through evaporation. (Corentyne back dam
savannahs and front land rice fields ; East and West Demerara salt front pastures).

The salt lands which are subject to regular or occasional tidal influx can
usually be recognized by their characteristic vegetation : Avuenma (Gourida) ;
Acro&ticum (Bear Grass) Sporobolus (Crab Grass) ; Pistia (Water Lettuce) and
Cyperus (Bizzi Bizzi).

In the inhabited and cultivated belt, natural surface waters are represented
mainly by flooded pastures and rain water collections ; the great majority of sur-
face water collections are made by man : these include drains and drainage
trenches, irrigation canals, canefields in flood fallow, rice fields, ponds and
borrow pits.

Our plan (Fig. .'>) shows the usual lay-out of irrigation canals, drains and
drainage trenches in cane fields. It gives an idea of the magnitude of the canal
problem in this country. We have calculated roughly that for every square mile
of cane cultivation (10-acre fields) there exist :

16 Miles of Irrigation Canals.

4.5 Miles of Drainage Side-lines.

45 Miles of 4 ft. Drains.

Drams and Drainage trenches rarely harbour larvae of A , darltngi probably
in consequence of the small volume of water in the former and the frequent
flushing in the water. We have never found this species in the 4-foot and other
smaller drains inside the cane fields ; small open surface drains, around villages
and estate yards, frequently harbour larvaj of A. tarsimaculatus and A. albdarsis,
but only very exceptionally those of A. dai lingi . In the front lands, many of
the larger drainage trenches or “ side lines ” in dry weather, tend to become
brackish* owing to leakage through the sea sluices at high tide.

Irrigation canals are, without doubt, the most important from our point of
view. They receive their water supply from water conservancies or from creeks
lying aback of the cultivation. These canals also constitute the waterway by
which cane is conveyed to the factories for grinding. 'The- main canals are
known as “middle walks;" at regalar intervals these give off blind ending
branches or “ oross canals." (Figs. 6 & 7.)

262 AOftlCtTLtfUftAIi JOURNAL OF BBtTlSfit GUIANA. [IX, 4.

The level of the water in the irrigation system is maintained constantly high
by pimping. In the main canals, the water is subject to fairly freqnent renewal,
and it presents the general characters of the inland river and creek waters we
have described, bat considerable variation exists, according to locality.

We dad that in Western Domerara the waters from the Borassiri and
Hababoo oonservancies and the Camooni Greek are very dark and very acid.
(pH 4 to 5.5, sometimes even lower). In East Demerara, the sngar estates
receive their irrigation supply from the Lamaha conservancy ; these waters are
less acid. (pH 5.5 to 0.4 and over.)

Blairmont and Bath receive their water from the Abary : at the pamping
station on this river, the pH. ranges from 6.4 to 6.8; the average of 350 pH
estimations taken in all sections of the irrigation system of these two estates, at
all seasons and over a period of 3 years, was 6.6. Readings under 6 were
recorded only on 5 occasions, the lowest value being 5.2; readings over 7 were
noted sixteen times with a maximum of 7.2.

Observations carried out at Port Mourant, on ttye Corentyne Coast, show
similar pH values for the irrigation canals, which get their supply from the
Caoje river.

The sodium chloride content of the irrigation canal waters rangeB, as an
average, from 20 to 40 milligrams per litre; except in some front land sections in
which readings of 30 to 100 milligrams per litre were sometimes noted.

In the middle walks the water is more frequently renewed; in the blind
ending cross canals, it is quiescent ; during the rains the reaction in the latter
canals is often considerably less acid than in the middle walk. In these blind
ends, or “ bucket heads, ” floating vegetation such as floating grass ( Paapalum ),
water hyacinth ( Pontederia ), Salvinia, and our floating mimosa ( Nepluma ), tend
to accumulate and spread. These cross canals, overgrown by vegetation and
sheltered as they are by overhanging cane, when the pH reaction is above 5.8, are
the favourite breeding sites of A. darlingi. Variation in pH reaction in these
waters, brought about by closing or opening the conservancy sluices, or by
excessive rainfall, undoubtedly affects the distribution and intensity of breeding
of this Anopheles in the irrigation canals. Larvae are usually absent in c&nalB
which are kept free from floating vegetation,

Flooded Fields : Flood fallowing is an important characteristic of the local
technique of cane cultivation : after &ree or four crops have been taken off a cane
field a small dam is thrown up arodfli it and it is flooded and left to lie fallow
for 6 months to 1 year. This practice has greatly increased the yield per acre
and is, therefore, of vital importance to the looal sngar industry.

^lood fallowing is also a feature of unusual importance to the malariologist :
at any time from one-tenth to one-eight of the cultivated land of an, estate is
flooded, often in close proximity to estate villages. For the first few months
after flooding a considerable amount of fermentation occurs from’tthe submerged

Plate V.

FI*. 8. —Flooded fields lying fa 1 low, \s hen co\cred with floating and vertical vegetation and favourably
may be productive source* of A dai hngt ,

Fig. 9.— Rice fields situated beyond the salt coastal front lands, and sheltered by trees and scrub, are
breeding sites of A dvrhnqu

Plate VI,

Fig, 1 0. — Open, windswept rice fields in the Balt coast front lands are fa\ounte breeding sites of A , tammaculatus , but only very
exceptionally harbour A. darhngi .

ItlLAftU IN BRIfiea GUIANA.

cane tops and stamps s the water is brown and has a distinct odonr ; vegetation is
scarce. At this stage we have never found flooded fields harbouring Anopheline
larvae.

After three or four months vertical and floating vegetation appears and
rapidly spreads (mainly Paspalum, Pontederia , Salvinia, Neptunia and
Limnocharis). The waters become clear and their pH ranges usually from 6.2
to 6.8 ; the rains have an important part in bringiog about this change in the
characters of the waters. At this stage flooded fields often become very pro*
d active sources of A. darling i. In gome localities we have completely failed to
find larvae of this species in spite of apparently favourable conditions.
Abnormally high salinity of the waters (100 milligrams per litre) or lack of
shelter and general situation and exposure of the field sometimes explain these
negative findings (Fig. 8).

Rice Fields : Rice is cultivated throughont the coast, aronnd and in the
immediate neighbourhood of most villages, on sugar estates and on some of the
creek savannahs. According to locality this cultivation is dependent on the
rainfall, on the irrigation system of sugar estates or on the seasonal creek
floods. Planting is done between March and June ; the fields are under water
from May to August ; reaping takes place in September and October. Usually
only one crop is planted and after reaping the fields are left to themselves till
the following season, most of them being flooded during the Autumn rains.

When the growth of the rice is well advanced rice field waters are usually
clear and light brown in colour ; pH ranges from 6 to 7 ; their content in soluble
salts varies within wide limits : in most front land fields tho sodium chloride
oontent is frequently well above 100 milligrams and sometimes amounts to
several grams per litre ; further inland it is usnally low, 15 to 50 milligrams.

The full grown rice plant offers good protection to mosquito larvae at its
base, in between the stems. Larvae of .1. tarsvngculatus are practically always
present and abundant. A. albitarsis occurs when the salinity is low. Under
the latter conditions .4. darlingi may ,be found, sometimes in large numbers,
when the rice fields are sheltered by surrounding trees and vegetation which
form wind-screens and offer a certain amount of shade. This species is
practically never found in the rice fields of the open, windswept front lands as
exist on the East Coast, north of the sugar estates and, more particularly, in
Eastern Berbice. (Figs. 9 and 10).

Borrow Pits : These exist in great numbers the length of the coast along
the rail and public roads ; scores are dug every year for the preparation of burnt
earth. Fortunately they are nearly all located in the windswept, salt front lands
and though very productive of Culex mosquitoes and A. tarsimacvlatus they
form unlikely breeding sites for A. darlingi . During heavy rains and where
suitable shelter exists borrow pits also may become dangerous breeding sites for
A. darlingi *

204 * AGRICULTURAL JOURNAL OF 6R1T i ISH GUI AKA. £lX, 4.

On sugar estates abandoned factory sites, with bush corned foundation
pits and obsolete canals, often present excellent conditions for the breeding of
the dangerous malaria carrier. (Fig. 4).

Ponds : These are particularly common in villages where, in the absenoe of
irrigation canals, they are used for storing rain water for domestic purposes.
A. taraimaculatus is nearly always present ; A. darlingi may occur when the
water is clear and sweet and if suitable shelter exists.

Flooded Pastures : Beyond the coastal salt land belt, flooded pastures when
sheltered and rich in vertical and floating vegetation, are dangerous ; the same
may be said of the bush covered rain swamps which collect on sand-reefs and
other abandoned lands.

In the salt front lands, where A. darlingi is usually not found breeding, this
species may occur, sometimes in considerable numbers, during heavy and
persistent rains which affect both the physio-chemical characteristics of the
waters and atmospheric humidity.

From this brief review it will be noted that a very , large proportion of the
water collections which favour the breeding of A. darlingi on the coast are man-
made and that they are essential and, therefore, unavoidable factors in the basal
agricultural industries of the Colony, sugar and rice.

Most of these surface waters, (irrigation .canals, flooded fields and many rice
fields) are not dependent on seasonal factors such as rainfall and floods ; they
are permanent, and as such offer, the year around, favourable conditions for the
breeding of Anopheles. Though season evidently still plays an important part
in the intensity of Anopheline breeding, we have found that A. darlingi on the
coast can be collected, both in its adult and developmental phases, throughout
the year. In the interior we observed this to occur only in proximity of white
water seepage swamps which offer permanent and suitable breeding sites. This
is evidently the reason why on those parts of the coast which are subject to
endemic malaria, the seasonal incidence of this disease is very much less clearly
defined than in the interior.

Both in the interior and on the coast our findings tend to demonstrate that
the breeding of A . darlingi is restricted to certain types of surface waters.
This species has a preference for water collections of considerable size. There
evidently exist certain characteristics of surface waters and soils which are not
congenial to this species and which, therefore, tend to limit its dispersion. We
believe that the following are some of such limiting factors.

Reaction of Surface Waters : A. darlingi is only exceptionally found in
waters with a pH value under 5.8; the optimum range is from 6.2 to 6.8.

A^Oane Grove, in spite of general conditions which would at first lead one
to expect the existence of severe malaria, we have found this disease only mildly
endemic (spleen rate : 16.1% and parasite rate 15,9% in 1937). The soil in this

MALAftIA t » BIUTISft GUtAHA.

205

locality is exceptionally acid. In April this year we found the pH of irrigation
canal waters ranging from 5.2 to 5.4 ; in some stagnant drainage trenches we
obtained readings as low as 3.5. We failed completely to find adult A . darlingi
in the houses or its larvae in any of the surface waters, in spite of the fact that
this species was at that time abundant all along the East coast.

At Wales, an estate with a particularly bad malarial reputation, the incidence
of this disease has shown a very distinct drop since 1934, coincidently with the
opening of a canal from the Camooni Creek to the Hababoo conservancy which
supplies the irrigation canals of this estate. Camooni waters are very acid
(pH 4.26 to 4.47 in April 1938). In August 1937, (with the Camooni and
Hababoo sluices open) in a search lasting several days, we completely failed to
find larvae of A . darlingi in the irrigation canals of this estate (pH 5.2), but we
found them common in flooded fields (pH 6.2 to 6.6). In April this year, during
heavy rains, with all the conservancy sluices shut, we found only a few larvae
of this species at the bucket head of a cross canal (pH 5.8); at the same time in
flooded fields and in the game locality (pH 6.6) larvae could be collected at
every dip.

In the interior a very large proportion of surface waters are strongly acid
and we believe that from a malariological standpoint they are not dangerous ;we
have, in fact, successfully controlled productive breeding sites by opening them
up to tidal invasion by acid river and creek waters.

Salinity ; A . darlingi is only rarely found in waters which contain over
100 milligrams of sodium chloride per litre* On the Berbice estuary in
three years we made only one such observation, the sodiutn chloride titro being
184 milligrams per litre.* The usual range is 20 to 60 milligrams, but in the
laboratory we have raised this species, from ovum to adult, in water containing
800 milligrams per litre.

On the coastal front lands and on the Oorentyne in particular very extens-
ive tracts of marshes are permanently and definitely brackish ; other vast areas
of surface waters become so in the dry weather tfirough contact with salt soils
and evaporation. Most of the rice cultivation in the Berbice front lands falls in
this group. All such waters, as not productive of A , darlingi , can be overlooked
in the carrying oitt of an aatbmalarial campaign,

•Since the present articlo was written, wo have found d. darlingi breeding in water with
a sodium chloride coutent of slightly over 3 grams per litre, at La Bonne Intention, on the
Bast Coast.

Larvae and pupae were found in a canal communicating with the damtned off terminal
portion of the main middle walk which, during the rains, is used to blow off to sea, through
a sluice, excess water from the irrigation system.

When this canal is stopped off from the main irrigation system as at present, at high tide
salt water leaks through at the sluice gate. m

We have found that the salinity in this canal and at the same spot where the larvae were
discovered varied within wide limits, in the couise of only 5 days the sodium chloride falling
progressively from 3.(550 to 0.400 milligr. per litre.

The breeding of A . darlingi in water of such high salinity Certainly remains a very
Unusual oecurxtnce.

S06

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

ClX, 4.

Atmospheric Humidity : This too we believe is an important factor which
limits the range of A. darlingi : the adult of this species is very susceptible to
desiccation and exposure to the strong coastal breeze rapidly kills it.

Some localities, though presenting apparently ideal surface waters, under
ordinary meteorological conditions are practically free from A. darlingi and
from endemic malaria. Plantation Bath is a good example ; the canals and
flooded fields of this estate receive their waters from the same Abary pump
which supplies Blairmont, a notoriously malarial locality. We studied these
two estates comparatively for three years (1034-1936) and came to the conclusion
that the drier atmosphere at Bath was responsible for the absence of A. darlingi.
It should here be remembered that this mosquito is a strict night flyer and
mainly a native of equatorial forest regions where the night atmosphere is
more or less constantly saturated with moisture.

We attribute the habitual freedom of the Corentyne coast from A. darlingi
and endemic malaria to a relatively higher atmospheric dryness and to the sal*
inity of the surface waters and soils throughout the inhabited belt.

The well defined seasonal malarial epidemics which have occurred at Bath
and on the Corentyne coast following the very exceptionally wet seasons of
1937 and 1938 tefld to confirm our views.

The factors which we have listed as controlling influences on the breeding,
and therefore on the dispersion of A. darlingi , exercise no similar influence on
the other local common Anopheles. Thie is particularly the case for A. tarsi -
maculatus which presents the most remarkable latitude in the choice of its breed-
ing sites : we have found this species breeding actively and evidently flourishing
in waters the pH of which ranged from 4 to 7.8 and the sodium chloride content
from 0.005 to 28 grams per litre. With such extraordinary adaptability practi-
cally all surface waters of this Colony are suitable for this species if cover is
provided in the form of vegetation or floatage for the protection of the larvae
from their natural enemies. Evidently the control of this species on the coast-
lands of Guiana would be a very arduous, not to say hopeless, task. Fortunately
this control is not required as this species locally does not act as a carrier of
Malaria.

We have thus concluded the study of the entomological aspects of the local
malarial problem in its principal lines.

Our findings are encouraging as only a single kind, out of the several local
Anopheline species, emerges from this investigation definitely indicted with the
transmission of malaria in this Colony. We have also fonnd that A. darlingi
has certain selective breeding habits and that its range of flight is equally subject
to certain limitations.

These findings infinitely simplify the malarial prevention problem, for they
allow til to direct our effort against well defined objectives with a good knowledge
of the vulnerable points in the enemy’s defences.

{To be Continued) '

THE GEORGETOWN BOTANIC GARDEN.

SOME NOTES ON ITS EARLY HISTORY.

E. B. MARTYN, B A„ A.X.C.T A.

Government Botanist & Superintendent, Botanic Gardens.

In the latter part of the 10th century, the formation of Botanic Gardena or
Botanic Stations was encouraged throughout the Colonies. In the West Indies
the Gardens at St. Vincent, the forerunner of them all, and those at Trinidad,
were already long established. The object of such gardens was primarily to
encourage the introduction of new crops, and Sir Joseph Hooker, Assistant
Director and later Director of Kew from 1855-85, took a keen interest in them.
They were in many cases, including British Guiana, the forerunner of later Agri-
cultural Departments and Experiment Stations.

It is not quite clear who was chiefly responsible for the initiation of the
Georgetown Garden, but in 1878 the Combined Court voted a sum of $240,000 for
the establishment of a Garden that was to be both a recreation ground for the
citizens of Georgetown as well as a site for the experimental cultivation of plants.
The area chosen for the new Garden, some 163 acreB in extent, was part of the
back lands of the old Pin. Vlissengen, and was purchased for a sum of 952,140.95.
It was selected as being close to the city, its position in the angle of the Lamaha
Canal also being advantageous for purposes of irrigation. Apart from this how-
ever, the site had little to recommend it, as the land had heen abandoned for
many years, and was trampled by cattle and largely overgrown by bnsh. In add-
ition the drainage trenches were choked up, and the removal of earth from
various places had added further to the swampy nature of the ground.

The task of designing the new Garden was ‘'entrusted to Mr. Prestoe, then
Government Botanist in Trinidad, who visited the Colony for this purpose in the
Autumn of ’78. On seeing the site he was immediately struck 1 by the two
avenues of Oronoque trees, relics of the old estate, the one running down the
line of the middle walk, from front to back of the estate, the other crossing the
former at right angles, near the front of the estate- On these two avenues, which
were to be left almost untouched, the plan of the new Garden was based.

Mr. Prestoe’s plan was forwarded to the Governor, (C. H. Eortright, Esq.,
C.M.G.) at the end of November, 1878, with a request that the area destined for
the nursery should be temporarily fenced as early as possible, and got ready for
tho raising of young trees and shrubs. The Garden was to be under the manage-
ment of a Board of Directors, and Mr. Waby, who had been Assistant Gardener
in Trinidad, was appointed to bo Head Gardener and to supervise the carrying
out of the plan until the arrival of the new superintendent, Mr. G, S. Jenman,
from Jamaiba, where he had been in charge of the Castleton Garden.

308 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 4.

Mr. Waby and his family arrived in the Colony at the end of December, ’78,
bringing with them a number of young plants from Trinidad, and Mrs. Waby has
left a good description of the conditions met with on their arrival. 0) After
being taken by Mr. Tinne, Chairman of the Directors, to see the site of the new
Oarden, Waby returned to his hotel horrified at the morass which he was
expected to tackle, and wished very much that he had Stayed in Trinidad. It
was a further disappointment to him that the Gardener’s house which he was
expecting had not even been begun. For the first three years he and his
family lived in a small house (the old Government Laboratory) at the top of
Brickdam which for some time also provided nursery accommodation, potting
sheds, and storage room for the Garden.

The first essential of the Garden was to obtain proper drainage, and to build
up the main avenue. The whole level of the front Garden, which was to be tile
drained, needed to be raised, the old middle walk navigation trench had to be
filled in, and side lines dug. Prestoe had planned a series of lakes which were to
give drainage and provide earth to ‘fill in dips and make undulating banks.’ The
roads, he considered, if built up and ‘round-ridged’, using r the subsoil mud, would
need very little surfacing ( sic ). As work proceeded, however, it was found that
more lakes than originally planned for were required, first to raise the level of the
ground sufficiently quite apart from making undulating banks, and also to pro-
vide large quantities of burnt earth to cover the avenue and the side paths, The
transport of the earth was facilitated by the use of a portable railway, first hired
from Booker Bros., and later purchased.*

Work on the new Garden was begun on January 2, 1879, and the first meet-
ing of the Board of Directors was held at the Royal Agricultural & Commercial
Society’s rooms on February 1. The Honourable J. E. Tinne was Chairman, the
other directors being the Honourable H. T. Garnett, the Honourable A. F.
McFalman and W. H. Campbell, Esq. (the last named eventually became Chair-
man in January, 1883, and always took the greatest interest in the Gardens until
his death in December of the same year). At the meeting Waby read his first
report, and it waB decided that each director in turn would supervise the work
for one week. It may be noted that at most meetings in the ensuing years not
more than two Directors were usually present.

The new Government Botanist and Superintendent of the Gardens, Mr. G.
S. Jenman, arrived in the Colony in August, 1879. Almost immediately after his
arrival he set out on a collecting expedition up the Corentyne River with Mr.

(l) Eleanor S. Waby ‘Forty Years’ Life in Tropical Gardens', Timehri, Vol. Ill, 3rd. series
No. 2, 1915, p. 285.

* This railway had a long and varied history. In December, 1883, when no longer required
at the Gardens, it was temporarily lent to the Public Works Department, end no further men-
tion of it appears for 34 years. In 1917 however, the late Sir John Harrison, Director of
Scienoedkia Agriculture, having presumably found the letter relating to the original loan in an
old fitawrote to the Public Works Department and asked for the return of the railway belonging
to the Botanic Gardens, and which had been temporarily lent! The Director of Public Works
replied however, that no trace of it could be found, ana that it had probably been used on the
sea defences, -

Plate VII.

Fxu 1. The Entrance Gates and Lodge to-day.

THB OTOBGBTOWN BOTAJTIC GABDBH.

209

im Thurn, who had already arranged to make a journey in this area in his capac-
ity as Cnrator of the Museum, and it was not until November that Jenman
returned to town and took up his duties at the Gardens. From that time until the
day ef his death — rather more than twenty -two years later — hia energy and keen-
ness provided the main driving force to complete the laying out and manage the
subsequent maintenance of the Gardens. Not many people in the Colony today
remember Jenman well, but from the records of his correspondence and minutes
it is possible to form a picture of him. A man of strong character and quick temper
is revealed in the copies, in his own hand, of a number of acrimonious missives,
both to the Directors and the Government Officers to whom he was responsible,
and also to his subordinates; but these records also make plain his great insight
into all matters horticultural, and his constant wish that the Garden should con-
tinue to improve and fulfil all of the objects for which it was laid out. After he
had laboured for two years, the Directors and himself received the highest praise
from Sir Joseph Hooker on the progress made, and throughont his career
Jenman received a number of well merited commendations on his work, both as
Botanist and Superintendent of the Gardens, from those best qualified to judge
in either sphere.

One of the matters requiring early attention was the housing of the Superin-
tendent and the Head Gardener ‘on the spot’. On his arrival Jenman took up
residence at the old Tower Hotel, and within a month or two his claims for cab
hire to and from the Garden were already involving him in arguments with Gov-
ernment. Waby, as we have seen, was temporarily housed in very inadequate
quarters at the top of Brickdam. It had been originally intended to build the Head
Gardener’s house on the piece of land opposite the Garden, now occupied by the
Department of Agriculture, but this idea was abandoned, and it was decided to
build both houses inside the Garden. The Wabys’ honse was finished at the
beginning of 1882, and they moved into it in February. A bungalow, built at
ground level, with more attention paid to its outward appearance than its internal
accommodation, it was a most unhealthy and uncomfortable residence. However,
it underwent a number of subsequent changes, 'which included raising it on
pillars, and altering the roof, which had originally sloped to within 3 feet of
the top floor. Today it is used as the Chemical Laboratory of the Department.

The building of the Superintendent’s house (now the residence of the
Director of Agriculture) involved Jenman, the Directors and the Public Works
Department in prolonged controversy. First there were delays in acceptance of
the plan, then in erection of the building, upon the completion of which Jenman
demanded a number of alterations, only some of which were provided. Finally,
though the building was finished in December; 1882, and the Government
Botanist’s office on the ground floor was used from that time, Jenman could not
or would not take up his permanent residence in the building until the middle
of 1883, as prior to this there was no proper bridge giving direct access to the
house and the only other means of approaching his new home was acroBS the
still unfinished Garden, from the main entrance gates of the latter,

210

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[IX, 4.

In the meantime, other construction work in the Garden had been going
on. The entrance gates, decided upon in February, 1880, were ordered from
England, erected in January, 1881, and have not been changed since. The
Lodge beside the gates was also built in 1880, with a front room where the
Directors could hold their meetings, and accommodation for a watchman. It
originally had a shingle roof, only replaced by iron sheets in 1932. This build-
ing was designed by the Honourable J. Brummell, Sheriff, who had become a
Director in February, 1879, and in May succeeded Mr. Tinne as Chairman, and
in whose office in Brickdam Directors’ meetings were held from that time until
the Lodge was ready. Mr, Brummell was one of the keenest of the Garden's
early supporters, and bis death in December, 1881 was a great blow. The
present Bandstand was eventually erected to his memory in 1889 and is certain-
ly a more worthy memorial than the drinking fountain first suggested as suitable
for this purpose. (It is of interest here to note that permission for the Militia
Band to perform in the Garden was first obtained in May, 1883).

Bnt to return to the Garden itself, the drainage and irrigation of the land
provided a series of difficult problems. As regards drainage, it was decided
that the Front Garden — some 20 acres in extent, should be tile-drained. Large
underground drains made with concrete slabs were laid down on each side of
the main avenue, and into these emptied the water from 40,000 feet of tile
drains. The latter were made at Pin. Montrose and laid in 1879 by Chinese
labourers from the estate, who were experienced in work of this nature. Five
years later they had become choked, and had to be cleaned, work again carried
out by the Chinese, and they once more had to be cleaned in 1889. Eventually
it was realised that such a form of drainage was not suitable for local conditions,
and after Jenman's death the open drains at present in existence were made.

To get the water away from the land, the Croal Street trench, which formerly
provided the only outlet, was not sufficient, and a tunnel was made under the
Vlissengen avenue to connect the north side line to the North Road trench,
the responsibility for deepening this and the South Road trench eventually being
amicably settled with the Town Council. Drainage however continued to be
poor, especially during wet weather, when the ground remained water-logged for
days on end, and in consequence the Superintendent’s and Gardener’s
houses became most unhealthy. In 1889, a drainage pump was put in at the
north western corner to drain the Flower Garden ; it was transferred in 1899,
to drain the Experimental Fields,* and later removed by the Public Works
Department.

Irrigation received early attention, and in 1882 a tall iron tank and pump-
ing engine were erected, and connected to a series of pipe lines throughout the
front Garden. Subsequently, it was found difficult to obtain sufficient preBBnre
in the tank, and irrigation by this method was never very successful. In later
years, open irrigation channels were used, and recently the original pipe lines,
the n&jority of which were found to be still in sound condition, have been in
great part connected to t he town water supply, whereby a suitable pressure for
*See footnote on page 211.

Plate IX.

*h»tol [Dr. B. B. Dahlgren.

Fiu. 3. — The “Oronoque Avenue,” now the Central Avenue through

the Park Lands.

Fig. 4— The Bandstand and Flower Garden

«n ewumcrn* sordine oaso*. su

watering k obtained, and this can be much more effectively carried oat. The
irrigation tank was dismantled and removed in 1936 .

The first 18 months in the life of the Garden was entirely taken up with
preparation of the land, and The work was somewhat hampered by very wet
weather in 1880. Planting, however, began in the middle of the latter year,
the oval, in the middle of the avenue, being the first area planted, after which
followed the border along the Vlissengen Road, the ground abont the lodge
(including the Eucalyptus trees which stand behind it today) and the line of
Bamans along the northern side of the Garden. As early as 1881 Jenman
remarked on the surprisingly rapid growth already made by the majority of
the new trees. Before the planting of any of the borders, however, the first
part of the Garden to be laid out had been the nursery, which was divided into
squares, surrounded by a Cherry Hedge (which is there still) and provided with
a temporary progagating shed, which remained until 1894, when it was removed,
having been replaced in 1890 by a more permanent erection, part of which
remains today. The sale of plants began in 1883. Amongst early plant intro-
dnctions raised were a number of grafted Mangoes and Litcheee, obtained from
Calcutta on an immigrant ship, and some canes from Honolulu, several of which
survived the 2 months’ journey despite the fact that they had been packed dry,
with the ends sealed, and formed the basis of the large collection of Sugar Canes
that were later used for Jenman and Harrison’s* researches on this crop.

The plan of the Garden included the Vlissengen Road Avenue, which was
to be planted with Saman trees that had been raised at Waby's house. The
construction of the avenue entailed considerable labour, as to give it the
necessary breadth the old trenches bordering the road had to be filled in and
new ones dug further out. This was pai t of the firat work undertaken, thongh
the avenue was not planted until January, 1881. Some difficulty was experienced
as the young trees grew up to prevent their leaning with the prevailing wind,
and their appearance even today shows that in not every case was this tendency
overcome.

The Central Avenue to the back of the Garden, or Oronoque Avenue as it
was then called, was planted in 1881, shortly after fhe Vlissengen Road Avenue.
The Directors originally decided to make this main avenue representative of the
principal forest trees of the Colony, but as many of these 1 would not thrive on
the Coastland, and as another alternative, namely a selection of fruit trees, would
have proved too great an incitement to petty pilfering, it was finally arranged
to use a selection of large growing tropical trees, the majority being American
species. The lower half of the Avenue was made 20 feet wide, and bordered by
trenches which were to act as reservoirs in dry weather and take off the surface
water after rain. The upper half was originally only 10 feet in widt h, and the

*Mr. Harrison aa he then was. arrived in the Colony in 1889 as Government Analyst in
place of Mr Francis who had died. The drat cane cultivation was carried out.on an atea of
4 acres, outside the south-eastern corner of the original Garden, and now forming the soathern
field of the Experiment Station. The field of tho present Station immediately south of the
avenne was taken into cultivation in 1899 when the work on cane was extended. The field to
the north of the avenue was cleared and taken in for rice cultivation circa 1903,

812“ „ AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 4.

ground through which it passed was left for some years in its original wild state,
with the idea that it might be used for planting trees suitable for timber or fire-
wood, This idea was never carried out, and eventually it was taken into cultiva-
tion to form the experimental station. In the early days of the avenue, the Or- .
onoque trees ( Erythrina glaum) formed its chief feature, though they have
gradually fallen, until today only two or three creeper covered relics are left. In
the drought at the end of 1887 the flowering of these trees was a remarkable
spectacle, as they were crowded with blossom, and at the same time all the
foliage was shed, which is not typical of this species of Erythrina .

Beside the Central Avenue, the two Serpentine Roads were laid out, but
were not surfaced, or connected by bridges to the main avenue for some years.
The Hippanai Trees ( Parkin pmdula) originally planted along them, did not
prove a success, and the Pithecellobiums and Palms bordering these avenues
today were not planted until 1888.

In addition to these avenues within the Garden however, it was originally
intended to make a drive (36 feet was the width first suggested) around
the outside of the whole area, and with this, end in view the D’Urban
Park gap was extended in 1881, chiefly with earth from the new south side
line.* After this the next operation was to have been the making of a drive
on the northern side, bordering the Lamaha Canal, but owing to the difficulty
of raising the surface of this road to be high enough above the level of the
Lamaha in wet weather, the idea was never carried out, and the North drivo
was not built, this strip of land being planted instead with shrubs and trees.
In 1882 a strip of land north of the canal was bought from Pin. Bel Air, and
planted with quick-growing trees to form a shelter belt for the Garden, which
land was subsequently given to the Town Council in 1925 and cleared to form
the site for the new Water Works and Pumping Station Buildings.

By October 1882, the original amount of $240,000 voted for the establish
ment of the Garden was nearly finished, and Government apparently considered
that the new venture was proving rather unduly expensive, for the Directors
were asked to curtail expenditure and told that in future the Garden must
be run on an annual maintenance vote. When asked however, what he
considered the expenditure would be in 1883, Jenman’s estimate totalled
$23,432 !

In May 1883 Jenman began to attend Directors’ Meetings regularly, and in
June the Directors were relieved of the financial business of the Garden and
Jenman had to requisition Government for money and account to them for its
expenditure in the usual manner of a Government Department, though the
Directors still acted in an advisory capacity. The relative relationships between
Government, the Directors and the Superintendent appear to have been rather

*Itmay be noted that the D’Urban Park Race Club Stand was from the beginning left out-
side%he Garden, cut off by a detour in the side liue trench as it exists today. Other stands
belonging to the club, which stood formerly on the land leased to the Directors, were removed
at their request when the land was taken over.

PlATE XI,

Fit,. 5. — The Iron Bridge o\er No. 2 Lake.

Plate XII,

Fifr. 6,— Jenman*«« House and Herbarium. now the residence of the Director of Agriculture.

THE GEORGETOWN BOTANIC GARDEN.

213

vague, but when in 1888 the Directors were informed that they were to have no
farther control over the Superintendent or the finances of the Garden, the
Chairman and two other Qireotors threatened to resign, and the two latter in
fact did so. By this time however. Directors' meetings were only held at very
infrequent intervals, and in May, 1892, appear the last recorded minutes of a
meeting.

As commonly occurs with concerns of this nature, the amount of money
provided for the upkeep of the Carden was often less than the ambitions of
those responsible for its appearance demanded. Thus in 1886, when a further
loan of 820,000 for the completion of the Park Lands area was exhausted, and
no provision made for their upkeep, Jenman was horrified to discover, on his
return from leave, that the vote for maintenance of the whole Garden had been
cut (by a majority of 1 on the division) from 810,000 to 87,500. He had previ-
ously stated that 810,000 was inadequate and considered 815,000 the minimum
necessary for maintenance. As a protest, declaring at the end of the year that
he could not maintain the Flower Garden with the money available, he dis-
charged all hands during December and left the area unattended, and in 1887
allowed the appearance of the Garden to become so bad that a reprimand was
reoeived from the Governor. In the ensuing year however, the vote was
increased by 82,000.

Glancing through the correspondence, minutes of Directors' meetings, and
other papers concerning the Garden, of which copies remain, we get some inter-
esting and amnsing insights into the affairs of sixty years ago. There is a note
on the price paid for labour in August ’79 — Foreman 64cents per day, Bhovelman
32-40 cents, women 24-32 cents. In May ’80 a clock and bell were requisitioned,
to ensure more punctuality over working hours. In '81 the closing of the
Garden to visitors after the official hours was strictly enforced. In *82 we find
one of the Directors involved with Jenman in violent conflict, conducted mostly
with the pen, over a matter of some coffee seedlings which the former had
obtained from the Garden while Jenman was on leave at a price which the latter
considered too low. In the end, the Director in question resigned, and after a
series of parting shots from all concerned, the action was broken off. In '83
Jenman was given a riding mule to use in the Garden and Waby had already
been supplied with a pony in 1879,* but the former’s subsequent application for
a horse and waggon was refused. In 1883 also there were constant bickerings
with the Public Works Department concerning the engineer in charge of the
irrigation engine. This individual, described as a Petty Officer of the Public
Works Department, was under the latter Department’s orders and would brook
no interference from the Garden Superintendent. The result can be well
imagined.

* This animal performed yeoman service for Government until Jane, 1899, when Waby
reports that ‘on Tuesday last it fell beneath me, all of a heap', and asks for another one, enclos-
ing a certificate from the Government Veterinary Surgeon to the effect that the pony in
suffering from ’stule deoay'.

814

AG&ICULTOUX. JOtfMUL Of WSttftXB, OMASA. [it, &

la Jane ’83 the Georgetown Bicyele Oiab applied for leave to make a brack
250 yards round in the Garden, for use of members. Though the application
was at first refused, iu the following year it reoeived the Directors’ support, but
nothing seems to have come of it. In ’84 the Tramway Company applied to run
their vehicles from the terminus in Croal Street up to the end of that street
and some 409 yards along the southern dam (i.e , the D’Urban Park Gap), and
this being objected to, applied in ’85, to come to the Garden main entrance.
This also wa 3 refused, though it was suggested they might stop in the Ylissengen
Road opposite the top of Charlotte Street, but the proposal was apparently not
followed up.

About this time we note a complaint by the Superintendent on the stealing
of plants from the Garden, usually by people who Bhould know better. In ’84 a
Horticultural Exhibition was held in the Garden, and in '85 there is an interest-
ing note that the Georgetown Cricket Club had asked for assistance in planting
a cherry hedge round their new ground. In 1885 also the Iron Bridges to cross
the first two lakes, obtained from England in ’82, were at last erected after many
delays. The Sun Dial in the avenue had also arrived 'in ’83.

In the early days of the Garden the traffic consisted chiefly of carriages,
but in the nineties we find this falling off, and the number of bicycles increasing,
somewhat to the annoyance of the Superintendent, who writes as follows in his
report for 1896-97 :

“Cyclists have created quite a demoralisation ; they care not for Rules
or remonstrances, and any kind of control is simply out ot the question.
My attention has been repeatedly drawn to the fact by other visitors,
entreating me to keep them entirely out of the place, and I know myself
of no gardens anywhere at home that cycles are allowed into, they being
confined everywhere, when off the street or high-road, to cinder-paths
of their own, in enclosed grounds, for practice or exercise ; and here,
also, they should be as absolutely excluded from the gardens. To all
other visitors they are an anxious nuisance, more particularly the silly
girls and giddy youths who appear carried away, particularly on Sunday
mornings when persons would like a quiet stroll, with reckless, aban-
doned exhilaration and levity, unable to control their conduct. ”
and again in the Reposrt for 1897-98 : —

“ Wheel Traffic . — Since 1894 there has been an unfluctuating steady

annual decrease in the carriage traffic in the gardens, due,

I believe, ...... to the still growing popularity of eycling with young

people of both sexes. Except in collisions and spills, there is an independ-
ence in bike riding that young people who have not yet begun to realise
the responsibilities of life are greatty taken with and that fills their minds

Plate XIII.

Photo] f ,>r H K I>ahlpren.

Fu„ 7 — Lotus LiUe& in a Lake m the Park Lands.

Tflfi (M0B6BT0WN SOTUflC GARDEN.

215

with cheerfulness Here is the record of the carriage traffic

since 1893-5 : —

Total carriages entered. Mean daily.

1894-5

12,044

1895-6

10,500

1896-7

9,908

1897-8

8,200

1898-9

7,715

Th? 3 e figures are particularly interesting. They show that since 1894

when the cycling interest and zest had taken on well, the carriage

traffic in the gardens has fallen 4,329 entries ”

During the ensuing years however the number of cyclists steadily increased and
the carriages still continued to fall away.

Wo may now turn to another aspect of the Garden. In 1889 a Zoological
Committee was formed, which in fact consisted of the majority of the Directors
together with the Superintendent, and arrangements were made whereby a
number of indigenous animals, including deer, waterhass, tapirs, etc. were kept
in the Garden. A good many losses were sustained, but new additions were
made to take their places, and the collection was kept up for many years. It was
in 1892 that the first pair of manatees was introduced to the lakes, and by 1896 these
animals had cleared the lakes of their natural vegetation to such an extent that
they had to be hand fed as they are today. With regard to the lake vegetation,
it is interesting to note that the Lotus Lily ( Nelumbo naeifera}, now plentiful
in the Garden, and to be seen in trenches in many parts of the coastland, was
first introduced in 1882, only one plant surviving from the seed planted. Two
other interesting introductions to which attention may be drawn were the
Double Coconuts (Lodotwa maldivica), first obtained from the Seychelles and
successfully germinated in 1893, and the Cajeput Tree ( Melaleuca h’ueadcndron),
seed of which was first sent by Sir Ferdinand von Mueller from Australia with
a glowing description of the value of the trees to dry up swampy land.

Mention must bo made of several subordinate officers who played a part in
the upbringing of the Garden. At the outset, Mr. Waby was assisted by a
planter, Mr. Howell, who had charge of the task work. In 1883 the latter
resigned and his place was taken by an assistant Gardener from Kew, Mr. Derry,
who three years later was transferred to Malaya, making way for Mr. Ward,
whose long and zealous services for the Garden only ended with his retirement
in 1926, after forty years’ service.

On Mr. Ward’s arrival, his duties included taking charge of the meteoro-
logical records, which were kept in great detail, a set of instruments having
been obtained from Kew in 1879, to which additions were made later. In this
latter connection, it is interesting to note some periods of abnormal weather
that affected (he Garden in the first two decades of their existence. In 1884*85

§16 idRiotiLttmiL JotmtrAt t>i vmiai GtiiAku. fix, L

there was a drought ; the years 1889*1893 were five consecutive abnormally wet
years, culminating with a record total of 135 inches in 1893 ; in the latter part
of 1899 there was another drought, only 52 inches falling during the year, but
it broke dramatically with the close of the century, on Old Year's night.

The first epoch in the history of the Garden closes with the death of
Jenman on February 28, 1902. He had lived to see his creation successfully
established, and had left a lasting memorial to his labours. Principally owing
to his dislike of travel by sea, which seems to have caused him extreme illness,
far beyond normal sea sickness, he had not left the Colony since 1886, even
refusing the Governor’s request that he attend Agricultural Conferences in
Barbados in 1899 and 1901, so that his Garden had indeed become his home.
He was buried near it, in St. Sidwell’s Church yard. Today, visitors are
reminded by the clock on the Lodge and a tablet below of the man to whose
inspiration they chiefly owe the Garden which they are seeing.

a water Rat (hoplochilus sciureus berbicensiS

Morrison- Scott) DAMAGING SUGAR-CANE IN
BRITISH GUIANA.

L. D. CLEARE, k.r.ent.s.,

Entomologist,

Department of Agriculture, Britith Guiana,

INTRODUCTION.

Rats are of common occurrence in the cane-fields of British Gaiana and from
time to time cause damage to an extent sufficient to necessitate special measures
being taken againBt them. These increases, however, are usually of short duration
and more or less limited in extent. On most sugar estates also a few men are
more or less regularly employed as rat-catchers, who hunt these animals with
dogs. In former years it is evident that rats were considered important enough
to cause the mongoose to be imported from the West Indian Islands.

Just what species of rats occur in the cane- fields has not been determined
previous to the present instance as far as the writer is aware, and it is probable
that there are other species which attack sugar-cane besides that dealt with in the
present account.

In 1936 there occurred at Blairmont Estate, Berbice, an outbreak of rats
apparently unprecendented as far as actual records are concerned both as regards
its proportions as well as duration and the damage inflicted, not only for that
estate but also for any other in the Colony.

About the same time there occurred on two other estates in Berbice, Pins.
Rose Hall and Albion, outbreaks of the same species of rat. These outbreaks
have not been dealt with in the present account as no special study was made of
them, but from reports and information received and a couple of isolated visits to
each estate it was evident that in a general way conditions on these plantations
simulated those on Blairmont estate, although in neither instance was the out-
break of the same magnitude as that of Blairmont estate.

In this connection the writer has been informed by Mr. R. B. Hunter, Manager
of Pin. Versailles, that about the year 1 889 a somewhat similar outbreak of rats
occurred at Pin. Bath, Berbice, when sugar-cane was destroyed also. Mr. Hunter
recollects especially that it was necessary on that occasion to replant a field as
the result of the destruction of the tops by the rats, and also having seen the rots
moving along one of the dams in numbers about dusk, apparently ooming into
the estate from th% adjacent savannah.

fei8 AdRiCUtTtfftAt SOXrf&kL Of BBlftafe GUUfcfA. tlX l

The Outbreak.

In November 1936, Mr. Q. M. Eccles, Manager of Bl&irmont Estate, consulted
the writer in connection with the outbreak and investigations were commenced.

The actual commencement of the outbreak Mr. Eccles informs me was in all
probability about December 1935, when it was found in reaping a variety trial
(field RP 24) that the plots of the seedling D 927/22 were completely destroyed
by rats and had to be omitted from the results. In April 1936, the rate were
first observed in large numbers in the cultivation, bat it was then considered to
be a seasonal infestation which would soon pass. At the reaping in October
1936 (Midlands 12-7) the seriousness of the attack was realized. It was then
found that extensive damage had occurred and the yield in that section was
seriously affected.

When the new ratoon crop commenced to spring it also was attacked, and at
the same time adjacent fields at a later stage of growth began to be attacked.

For a while this condition continued, but later the damage appeared to cease,
and for a few months little activity of the rats was observed. It was hoped, then,
that the outbreak had terminated. In November ot the same year however, it
was evident that the rats had become active again, and damage was fairly preva-
lent in young fields. From that time to about the end of 1937 with only Blight
interruptions the rats continued to damage the crop to a serious extent.

By March 1938 the outbreak had apparently ceased and while rats were by
no means absent they were not causing any serious damage.

For the period November 1936 to December 1937 the total number of rats
destroyed on Blairmont Estate was 127,449 made up of 25,543 caught after fields
had been reaped either as the result of Hooding or in weeding and the changing
of trash banks, and 101,996 caught by means of dogs at other times during the
growth of the crop. At Pin. Bath between December 1936 and December 1937
the figures were 53,157 and 33,869 and 19,288 respectively.

Nature and Extent op Damage.

As previously mentioned, the damage by the rats was first observed in canes
at reaping. In these fields canes were found lying on the ground as the result
of lower joints being gnawed by the rats, the cane subsequently breaking off and
falling.

In high cane examined by the writer in November 1936 this damage wag
fairly prevalent. Although usually only a couple of joints were gnawed, at
times as many as six or even more joints were destroyed in this way. Almost
always such damage was confined to the lower parts of the stalks regardless of
their height (Fig. 3). Occasionally however, a few joints higher up, and even
as high as six feet from the ground were damaged.

%n older canes sometimes the top of the cane was damaged. In such
instances the central leaf and growing point of the stalk was eaten. Following
this damage the stalk invariably commenced growth afresh from the buds lower
down (Fig. 4). 8

Plate XIV.

Photo]

i »

I*. 0. Cioaro

..... v a

A WAtte feAf l>Att AGING StJGAR-CANB *» N&l'tlSH GUIANA. 210

In young fields where the stalks were sot more than a couple of feet in
height the damage took the form of gnawing of the shoots close to the ground.
Shoots thus severed were not as a rule entirely eaten but were chewed and the
juices sucked, the fibrous matter being discarded to a large extent.

As to the extent of the damage some 1,500 acres on the Blairmont estate
were involved, comprising principally of the sections Ram poor, Midlands, Olivier
and Abary at Blairmont, Versailles and Locarno end to lesser extent Flanders,
Old Bath and Diligence at Bath.

The loss caused through the rats, like all field losses, is not easy to assess,
bnt Mr. O. M. Eccles as early as November 1036 had estimated that in a single
week’s working there had been a drop of “ 100 tons (of sngar) on the estimated
yield from a block of first ratoons, entirely due to rat damage ” (in litt.).

Estimating the loss due to the outbreak Mr. EccleB writes : —

“ To assess the actual total damage is impossible. Apart from the direct loss
“ from rat-eaten canes, we do know that we definitely had to throw out of culti-
“ ration 225 acres, of which the spring was so badly attacked as to kill out the
“ stools altogether, but for this these fields would undoubtedly have been carried
“on as ratoonB for two or three years more according to ratoonage.”

It was estimated that the loss in sugar on the Autumn crop of 1937 was in
the vicinity of 1,200 tons.

As to the loss in individual fields, or groups of fields, the yields of certain
fields are given below, as plant canes and as 1st ratoons.

Section.

Field.

Yield Plants.

1st Ratoons.

4.02

2.22

3.90

1.73

Midlands

3.61

1.43

(10 acres)

12-7

5.66

1 ’ 2.96

The Rat.

Specimens of the rat were submitted through the courtesy of Sir Guy
Marshall, Director of the Imperial Institute of Entomology to Mr. T. C. S. Morri-
son -Scott, of the Department of Zoology (Mammals Section) of the British
Museum (Natural History) for determination.

Mr. Morrison-Soott determined the rat as a new Bubspeoies of Hoplochilua
sciurem which he called berbiccnsia, and a description was published by him in
the Annala and Magazine of Natural Ilistory, Ser. 10. vol. XX, pp. 535-538,
November 1937, in a paper entitled “ An apparently new form of Cricetine from
British Guidha.”

220

AGRICULTURAL JOURNAL olf BRITISS GUIANA faX

The following are the measurements and description as given (loo. dt.).

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A WATER RAT DAMAGING SUGAR-CAlfaS IN BRITISH GUIANA. 221

“ Deaoription — Head and body dorsally a blackish olivaceous brown due to
“a mixture of yellowish buffy-brown hairs and black hairs, black predominating.
“ Flanks clearing to cinnamon-buff. Arms and legs like flanks. Ventrally
“smoke-grey, washed with yellowish cinnamon, strongly so on middle of belly.
"Hands same as back. Hind feet greyish bnff. Tail grey.

“All from same locality and caught in same month. Skin-measurements by
collector in flesh.”

Mr. MorrisOn-Scott compared the specimens with 27. guianac Thomas
(Ann. and Mag. Nat. Hist. (7) VIII, p. 149, 190) and gives the following
characters :

27. sc iu reus berbicensis.

1. Strong admixture of black
hairs dorsally

2. No rusty tinge on back

3. Tail grey

27. guianac

1. No black hairs dorsally, dark
brown at most

2. Rusty tinge on back

3. Tail reddish-brown.

The type locality of II. guianac Thomas, is Kanaku Mts., British Guiana.

Finally, Mr. Morrison- Soott concludes : “ It looks as though sciureus is not
“confined to the Amazon drainage area but extends into the savannahs of
“ British Guiana, and that berbicensis is just a coastal form. ”

Since the publication of Mr. Morrison-Scott’s paper further specimens have
been submitted to him.

Of two specimens from Pin. Versailles, West Bank Deinerara, Mr. Morrison-
Scott says (in litt.) :

"Nos. 1' 9 and 19. These are Without doubt berbicensis. True they are larger
“than the type. [The length of head and body were 210 mm. and 200 mm.
“respectively— L.D.C.] ... A fairly reliable index is to be found in the teeth
“which do not alter much and No. 18 has the maxillary tooth row exactly the
“same length as the type and No. 19 has this row 0. 15 mm. sihaller. The
“condylo-basal lengths are No. 18—38.00 mm. and No. 19 — 38.95 mm. ”

As regards two other specimens which had been in captivity for some
seven months and in which a reddish coloration had developed a couple of weeks
before they were killed, Mr. Morrison Scott says—

“ Nos. 21 and 22 are exceedingly interesting. They approximate very
“closely to the type of guianac but their tails are not reddiBh-brown enough
“(the root of 21’s tail is about the right colour). I do not think the red is
“seasonal because they were killed at the same time as 18 and 19. I wonder if it
"is some condition of captivity ? The patch of red on 22’s head seems abnormal.
“I should be extremely interested to hear if you get any wild reddish forms—
'* guianac (= Sciureus) may of course overlap with berbicensis. ”

AGRtCTTLTtmAL JOtfRSAt 6F BRITISH GTTtASA.

t!t, 4.

222

The male of I berbicensis is both larger and heavier than the female. Meas-
urements have been given already. The average weight of 12 males was 167.1
grammes with a minimum of 111 gms. and a maximum of 220 gms., while the
average of 10 females was 96.7 gms., with a minimum of 61 and maximum of
133 gms.

Ecology.

Habitat .-—At the rear of Blairinont Estate and the adjoining Pin. Bath and
separated from the actual sugar-cane fields by only the empoldering dam and its
canal is a vast savannah. During the wet season this savannah becomes Hooded,
to a depth of about eighteen inches to two feet of water.

The vegetation of this savannah is principally the sedge known as “ Bizzi-
bizzi” ( Gypcrns articulate L ). Interspersed amongst this, in old water courses
which are known as “creek hands”, grows the broad-leaf bamboo-grass or
Missouri grass as it is sometimes called, Hi/mcnmhm * aniplexiraulis (Rudge Nees).
There is also in places areas of Hrluotua, probably H. psitlicoruin L. while on
fringes which abut the dams of the estates is also Panu um luxum Swartz.

The outstanding feature of the area as far as the outbreak of rats was
concerned was the areas of bamboo grass This grass which forms rather thick
clumps appears to offer conditions suitable to the rat for breeding and it is
believed that this is their natural habitat.

When the investigation commenced it soon became apparent that the fields
principally attacked were those situated adjacent to the savannah aiea. For
instance, the attacks in May 193(5 occurred in M. 7/12 section, and it was not
until the following year that the rats had penetrated to M. 1/6.

Similarly, when the writer first visited the estate in this connection it was
the Abary sections that were suffering from attacks of the rats.

Later it was found that similar conditions as to proximity of attacked fields
to savannah held good at Pin. Bath also, for although the rats appeared in the
sections Old Bath and Diligence on that estate which are situated at the front of
the estate these sections have savannah areas in their rears,

A careful examination in the Abary fields at Blairmont when they were
first visited revealed “spoor” of the rats which indicated that the animals were
crossing the dam and trench separating the section from the savannah. Farther,
most of the damage ocourred at the savannah ends of these fields.

All the field conditions, therefore, pointed to the rats having invaded the
cultivation from the adjoining savannah. This was farther confirmed by the
statements made by East Indian labourers who had crossed these savannahs to
the effect that large numbers of rats which had been drowned were seen in the
savannahs and that in places where the land was either higher or in little
hammocks, many rats colleoted.

A WATER BAT DAMAGING SUGAR-CANE III BRITISH GUIANA. 223

Food and feeding habits- — la their attacks on sugar-cane the rats fed beth on
the young eane-shoote as well as on hard cane, and even on the “tops'’ of tall
oanes, according to the growth of the fields.

When yonng fields are attacked the shoots are entirely severed and portions
of the softer white tissue at the base are consumed, the major part of the shoot
being left uneaten on the ground with finely gnawed tissue.

In the older fields where joints hare been formed these are gnawed, in most
instances the joint nob being entirely severed, but the stalks often break as the
result of bhis damage so allowing farther gnawing along the length. In this way
the same stalk may be eaten over a period of several days and a number of
consecutive joints destroyed, extending sometimes for a length of more than two
feet of stalk.

While all varieties of cane were attacked there was a preference which was
quite marked — thus Diamond 10 appeared to be preferred to D. 625, while other
preferred varieties were Co 213, D 927/22 and D 74/30. Thi3 variety preference
was so marked that in different trials the seedlings D 927/22 and D 74/30 were
damaged to such an extent as to prevent suitable samples being obtained for the
purpose of the experiment.

The natural food of the rat there can he little doubt is the stalks and seeds of
grasses in the savannahs, and the stalks of bamboo grass are often quite as
succulent as those of young sugar-cane. Instances have been observed also
where the rats fed on the stalks in clumps of razor-grass ( Paspalum virgaium L.)
on dams situated between the savannahs and fields. This grass is, however, not
an inhabitant of the wet savannahs which are the natural habitat of the rat.

In laboratory rearing the rats were kept for many months feeding readily on
on young cane-shoots, shoots of guinea grass (Pan i cum maximun Jacq.) and also
on padi.

In feeding, after the shoot has been gnawed the rat takes a portion in its
hands, then sitting more or less upright proceeds'to eat it using its hands to hold
the food. When feeding on padi the grain was held to the mouth in the same
manner while the outer shell was removed, the grain being then consumed and
the husk discarded.

Iu the laboratory a fair amount of water was taken also.

In the field, feeding appears to be entirely nocturnal, or at least at dusk and
again also in the early morning hours. This was so in the laboratory also, at
least at the beginning, but after rats had been in confinement for some time
they would commence to feed when supplied ‘ with fresh food about 4 p.m.
although they were never observed to feed earlier than this or later than about
9 a.m., except under stress of hunger.

The amount of food consumed has been determined as regards padi as this
was a convenient material to work with. For one lot of 28 rats over a total

224 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 4 .

period of 574 rat-days, the average consumption of padi per day was 11.2
grammes per rat, while for another lot of 21 rats over a total period of 113 rat-
days, the average consumption of padi was 9.7 grammes per rat.

Conditions conducive to outbreaks . — As to the conditions which bronght
about the ontbreak we can form an opinion only in so far as the conditions
observed some months after the rats had become prevalent will allow.

That the rats came from the savannahs in rear of the estates there is no
doubt, and likewise there can be no doubt that these savannahs are their
natural habitat.

Whether severe and excessive floodings of the lands, or an over-population
of the area was the primary cause of a migration of the rodents to the adjacent
cane-lands, it is not possible to say. The fact remains that snch migration did
occur and that the savannahs, at least in November 1936, were flooded to an
abnormal height. When the rains subsided later the catches of rats diminished,
but again increased some months after when the next wet season occurred, and
kept up as the numbers of rats show, to some extent during 1938 which was a
particularly wet year. '

The number of rats caught in the different sections, with total and the
number per acre, show that it was the sections adjacent to the savannahs which
in the beginning were moat severely attacked, both at Blairmont and at Bath,
the intensity diminishing and the attacks taking place later as they extended
away from the savannah. Later, however, as the rats spread through the areas
some of the most severely attacked fields were situated at some distance from
the savannahs.

As the outbreak continued there was a gradual advancement of the rats into
the longer established areas of cane, and there can be little doubt that this
species of rat will become, if it is not already so, a permanent resident of the
cane-fields. The rats from Pin. Versailles (Nos. 18 & 19) were taken under
ordinary conditions in cane-fields, and it would seem that in this area at least the
permanent association with cane-fields has already occurred.

It has been suggested that the rats were attracted to the cane and to attack-
ing it by some condition and change in its composition, imperceptible to
ourselves, brought about by waterlogged conditions of soil which are associated
with newly-empoldered savannah lands, and that this was the primary cause
of the outbreak and farther, that as such lands became “ better drained ” the
outbreak would automatically cease.

It is impossible with our present knowledge to prove that such is not the
case, end the fact that later the outbreak ceased would seem on the face of it to
substantiate this. It is true also that in newly-empoldered fields water-logging
dags occur at times, and that in some of the fields at Blairmont estate there were
indications of such being the case, and that in such fields rats did cause consider-
able damage. This was not by any means general of the fields attacked, however,
and certainly was definitely not so of certain fields which the writer observed in

A WATER RAT DAMAGING SUGAR-CANE IN BRITISH GUIANA.

225

November 1936, where young canes were being severely damaged by the rats.
Against that, too, we have the fact that the outbreak although originating on the
recently empoldered lands was not confined to it, indeed, as far as Blairmont and
Bath were oonoerned, aotually was as severe on some sections which had been
empoldered years previously as on those only quite recently taken in. In addition
of course, we have the taking of the rats at Pin. Versailles in fields of long stand-
ing.

With the older established fields, even when these are adjacent to savannahs,
it appears that razor-grass (Puspalum virgatum L.) on dams plays an important
part in serving as an intermediate in the spread of the rats to the cane-fields.
After an area has been taken in, razor-grass soon establishes itself on the dams
and at times forms a very definite and extensive association in such places, some-
times almost to the exclusion of the other grasses which were previously growing
there, and while it does not ever completely take over the dams it may become
the dominant species (Fig. 2).

Under such conditions the dense clumps of this grass have been observed to
act not only as cover, but to serve also as nesting places for rodents, and it is
believed that it may thus form a nidus for the rats.

Although it has been stated that the number of rats caught per week shows
some correlation to the rainfall this should not be interpreted too literally and the
prevalence of the rats considered entirely as seasonal. Consideration must be
taken also of the fact that when these rats invade cane-fields they live in the
interstices of the soil, made in the course of its cultivation with an agricultural
fork, and with the advent of heavy rains they are driven from such places and
are then more easily caught by dogs and labourers. These rats have not been
observed to make burrows, but this may be due to the large amount of cover
offered as the result of the method of cultivation as mentioned.

Natural Enemies . — The principal enemy of Hoplochilus observed in the
outbreak was an Oestrid larva. Although not abundant it was of frequent occur-
rence and accounted for a fair number of rats, not perhaps directly in itself,
although the injury inflicted in this way was sufficiently important, but more
usually through the septic condition which followed as a result of its attack,
and the secondary infection of Cochlyomyia that often followed in its wake.

The Oestrid larvae were usually situated behind the arms of the rat but
sometimes also a little further along the body in the vicinity of the ribs. While
usually only a single larva was found on a rat, sometimes as many as three would
occur in one host.

The fly concerned has been determined as Cutebra apicalis Guer. by
Dr. Van Emden through the Imperial Institute of Entomology, London.

A mite also was found frequently on these rats but this is of no economic
importance, #

226 AGRICULTURAL JOURNAL Of BRITISH GUIANA. ftOK* 4

While we have no proof that these rats are attacked by ssu^ee,
conditions observed point to this. On the empolderiug dam between the
savannah and the newly taken in fields, the water snakes Liophia cobella Linn, and
Helicops angulata Linn, were prevalent, and in the olnmps of razor-grass ia
which the nests of rats were frequently found, egg-masses of these snakes were
of frequent occurrence.

During the rat outbreak there was a marked increase in the number of
snakes also, bnt they diminished with the lessening of the number of rats.

Control Methods.

Hunting .— The first efforts at control directed against the rats was hunting
with dogs, and this continued throughout the campaign. This is the method
adopted on sugar estafaas as routine against the normal rat population of the cane-
fields, and it is bnt natural that it should be extended when conditions became
more acute. As to its value as a means of control in epidemics of the nature of
the one here described it is open to much discussion.

Still with a pest attacking large areas of crop and causing losses of the
extent shown above, it is only reasonable to adopt snch measures as appear
effective on the face of them.

The actual figures of numbers of rats caught as given below do not show
that the catching of large numbers of the rodents had any immediate or percepti-
ble results, and one is left to conjecture whether there wonld have been any
material difference in the position for the worse were such measnres not
undertaken.

The method of hunting consisted merely of men going through the cane-
fields, and over the newly empoldered lands, with more or less trained dogs
which located the rats and drove them from their hiding places. The rate were
then seized by the dogs and killed, bat were secured by the men before the dogs
conld devour them as payment was by results on the number of rats secured.
The dogs nsed for this purpose comprised a miscellaneous collection of mongrels
of particularly lean and halfstarved appearance generally grouped under the
non-committal term of “hunting dog”, which, nevertheless, were very efficient at
the work (Figs. 5 and C).

Plate XVI.

[L. D. Cleare.

x auiuj ^

Fk. 5 — Ratcatchers with clogs w orkmg over savannah recently empoldered and ploughed.

Photol (L D. Cleare.

Fig. 6. — Ratcatchers with their “ hunting dogs ” working in taller canes.

i Wat'hr sat? Damaging stfGAR-cAini is iaWifitf gWaSa. 22?

The number of rats caught on both Blairxnont and Bath estates are given
below month by month for the period November 1936 to October 1938.

Blairmont Estate

Bath Estate

Total

1936

November ...

1,153

December ...

36,047

2,008

38,655

1937

January

23,202

7,942

31,204

February

9,044

11,746

20,790

March

7,200

7,798

15,058

April

5,741

11,574

17,315

May

10,0<S7

4,296

14,983

June

8,247

1,790

10,037

July

4,589

913

5,502

August

5,302

1,245

0,547

September ...

3,654

255

3,909

October

1 3,485

1 330

3,821

November ... ..J

1 3,698

788

4,480

December ...

4,680

2,460

7,146

VXib

January

8,081

860 1

8,947

February

1,894

1,051

3,545

March

1,202

2,582

3,784

April

2,811

3,118 '

5,929

May

4,139

1,421 ,

5,560

June

930

42 '

972

July

1,847

223 I

2,070

August ... ...'

4,597

087 1

5,284

September ...

1,935

144

2,079

October

M I

Total

154,951

03,909 1

218,860

Poison Baits,-— Within recent years there has grown a considerable literature
On rat control, and papers on this subject have been published in many parts of
the world. In many instances the publications have been concerned with the
common house rats (Mus) although some deal with field rats and even species
attacking sugar-cane. In most of these publications poison baits artfrecommend-
ed consisting principally of red squills, barium carbonate or white arsenic, and
more recently thallium sulphate has come into considerable favour, in
Combination wjjh substances considered to be attractants.

AGRlCULftttUL JfOUMAt OS' SRttlSH QtflAUA, tlX, 4.

So when hunting with doge did not appear to rednee materially the numbers
of rats and other methods were sought, this was the line of attack which was
taken. Phosphorus baits were first tried in the old West Indian form of “sulphur”
matches stuck into bananas, which at the time was giving good results in
Trinidad against rats in cacao-fields. Here the bait was not successful ; the rats
soon learnt to recognise it and either did not take the bait, or removed the
matches and consumed the portion of the fruit which was not affected I

Other baits then received attention. Stock formulae recommended and uBed
elsewhere with barium carbonate and white arsenic as their bases were tried,
and later substances other than those usually recommended as attractants were
used with the hope of increasing their efficiency. In this way most of the easily
obtainable food substances were used including bananas (ripe and green) bread,
butter, cheese, fish (salted cod), Hour, lard, oats, (grain and meal), oil, cotton-
seed), padi, potatoes (English and sweet), maize (grain and meal), and
saocharine. Sometimes in addition aniseed oil very diluted was added as an
additional attractant. Later several proprietary rat poisons received attention as
well as rsrt virus.

At the outset it must be stated that, all of the substances mentioned
previously, and all of the proprietary rat poisons, were taken by the rats to a
greater or lesser extent, and when fed to laboratory ruts sooner or later proved
fatal, with the exception of rat virus, which probably had deteriorated in
transit. In spke of this it was evident that none could be considered as being
likely to prove a successful means of control for these particular rats.

The most successful of these baits proved to be padi upon which was
sprinkled a proprietary rat poison of which arsenic trioxido was the active
constituent. A variation of this which provod to be highly toxic was padi
sprinkled with Paris green.

In the padi-arsenical trials it was revealed that the rata in feeding on the
padi removed the husks and ate principally the grain within. It was evident
then that any poison to be used should penetrate into the grain. Sodium
arsenite in aqueous solution of 4 per cent, was therefore tried. Padi was
soaked in this solution for 24 hours, then removed and allowed to dry by air.

In laboratory trials the bait was taken freely at first Mid proved extremely
toxic, as little as 1 gram of treated padi (about 15 grains) being a fatal feed.
In the field, too, where the bait was set ont in “torpedoes,” (t.c., in a Wow’ of
protecting paper) it was readily taken at first, and no donbt was equally effective.
As with other baits the rats soon became “wise” to the presence of the poison
and then did not take it readily. In fact in the laboratory after a time, even
under the stress of no alternative food for several days, the rats refused to feed
upon padi so treated, bat when untreated padi was substituted they fed
immediately and extensively.

% Thallium sulphate baits, made to the usual formula bnt with padi in place of
wheat at the rate of 1 to 500, pat up in “ torpedoes” was readily taken and the
rats did not appear to detect the presence of this substance. .With this bait it

a Water rat damaging sugar-cane in British guiana. 229

ml evident that the amount of thallium would have to be increased if the bait
was to be effective. About this time (March 1938) the numbers of rats caught
began to decrease, damaged canes seemed less in the fields, and trials with baits
were discontinued.

In placing baits in the fields, especially during periods of heavy rains, it
was found that “torpedoes" did not offer an efficient protection and as a result
the baits deteriorated rapidly, farther, the “torpedoes" were sometimes punctured
by ants. The best results were obtained by setting out the baits in galvanised
iron pans, or enamel-ware plates about 10 inches in diameter under roof -shaped
galvanised covers of a sufficient size to afford complete protection, with the
openings directed away from the prevailing wind. Although baiting in this way
is not as easily done as with “torpedoes" no difficulty was experienced as
the covers and pans are both light and easily porbable, and the protection offered
more than offsets this.

The indications from these trials of poison baits was that arsenicals,
especially sodium arsenite in aqaeous solution absorbed by the padi, and
thallium sulphate, are both useful poisons for these rats, particularly the former
on account of its inexponsivenesc.

Further work would need to bo carried out in connection with sodumi
arsenite on the minium fatal dose and also the finding of some means of making
the padi more attractive and/or disguising the presence of the poison in baits,
should this be necessary when less poisonous amounts are used.

As for the situation at the present time, Mr. Eccles writes, “ while the
“ punt-loaders still seem to catch a fair number of rats, there are practically no
“signs of damage either when one rides around the cultivation or goes into the
“ fields. In fact, had it not been for our past experience, we should certainly
“ not be bothering to catch and pay for rats now, as we should have said we
“ ‘ hadn't got any ! ’ ”

Summ \RY.

An account is given of an outbreak of rats which occurred at Rlairmont
Estate, Berbice. The species of rat concerned was found to be a new subspecies,
namely Hoplochilu s sciuieus bcrbicensm Morrison-Seott.

Similar outbreaks occurred on other estates in Berbice about the same time,
although these were not of the same magnitude.

The ecology of the outbreak is dealt with, and some account is given of the
means adopted for dealing with it.

Acknowledgments.

In preparing this account the writer is very conscious of the extent to which
he is indebted to Mr. Q. M. Eccles, Manager of the Blairmont Estate. The
situation of the estate at Borne distance from headquarters and the pressure of
other work prevented frequent visits being made, and as the result much of the
routine work and the trials with poison baits was oarried out under the super-
vision of Mr. Eccles, who, moreover, deputed Mr. L. R. Barker, formerly
Deputy Manager, and Mr. J. A. By water to assist with the work.

A S&ORT HISTORY OF THE RUPUNUNI SAVANNAHS
WITH SPECIAL REFERENCE TO THE LIVESTOCK ‘

INDUSTRY.

H. E. TURNER,

General Manager , ltupununi Development Co. Ltd.

Civilization came to British Guiana mainly through the medium of the
Dutch. They occupied the coastal lands and such alluvial belts as lay along the
various rivers within tidal influence. Sugar, Cotton, Coffee, Cacao, etc., were
grown for export, and labour in the form of slaves from the West Coast of Africa
was supplemented by the enslavement of Aboriginal Indians, stronger tribes often
capturing and trading their weaker neighbours. As the supply of Aboriginal
Indians became exhausted close at hand, expeditions were led higher up the
rivers and military posts erected at strategic points. A small military post was
built at the confluence of the Rupununi and Essequibo Rivers, and eventually
the open country to the south, which is an offshoot of large savannahs of the
Rio Branco, was discovered. No attempt was made by the Dutch to settle the
savannahs of the Rupununi.

At the same time, civilization was proceeding along the Amazon through
the medium of the Portuguese, who discovered the large savannahs of the Rio
Branco, and used them as a dumping ground for all criminals under long sentence
Of imprisonment. To assist these deported prisoners, the Government sent up a
small number of cattle, and it is from this nucleus that have sprung the large
herds that have formed practically the sole support for an ever-increasing popu-
lation in the Rio Branco District of Brazil and the smaller savannahs of the
Rupununi District.

Towards the middle of the last century, British and Brazilian interests met
horth of the Kanaku Mountains midway between the Rupununi River and the
Takutu and Ireng Rivers. British missionary met Brazilian rancher near the
site of the mythical lake Amaku, on the shores of which the early adventurers had
boped to find the golden city of Manao. A clash ensued; each side was backed
by its respective government, and armed forces were dispatched and faced each
other near the Macusie Indian Village of Pirara, where a mission had been
established. Eventually both sides withdrew and in 1906 the disputed area
was finally awarded by arbitration to British Guiana.

Riohard Schomburgk in his “ Travels ” gives a highly coloured picture of
Conditions at Pirara when he first visited there in 1842 in company with the
British armed expedition. His account of Brazilian ranching activities should
be taken with the proverbial ‘grain of salt*, At the time, it is doubtful if there

A SHORT HISTORY OF TH8 RTTPUJTOKI SAVANNAHS, 831

was a single ranch or outstation established on what is now British territory.
Stray cattle no donbt had crossed the Takntn and increased in the nnoccupied
country towards the Rupunnni. Schomburgk speaks of rich pastnres, large herds
of cattle, galloping vaqueroa, etc., but what he in all probability witnessed
was the annual round-up of a few hundred head of stray cattle.

The Rupunnni Savannahs are divided into two almost equal parts by
the Kanaku Mountains which run from east to west to within three miles of
the Brazilian border. At this period, the southern half, now held by the Rupu-
nnni Development Co., Ltd., was entirely in the hands of the Aboriginal Indians,
without encroachment by either British or Brazilian. Slave raiding by the
Brazilians seems to have been prevalent and Schomburgk describes raided and
bnrnt Macusie Villages in the Eanaku Mountains. Inter-tribal warfare also, no
doubt for the purpose of taking slaves, still went on, and many years ago the
writer heard the then oldest member of the Wapisiana tribe describe how he
was taken as a small boy to see the site of the last big fight and found discarded
weapons still scattered about.

Latterly, however, the remaining Indians were left in peace, and by the
middle of the last oentury were in sole possession of the savannahs with appar-
ently little or no external influence affocting their mode of life, habits or
economic outlook. A few white men toured the llupununi from time to time in
search of minerals or in scientific exploration, but the long, slow and costly
transport of that day presented too many difficulties to encourage permanent
settlement.

Some time between 1860 and 1870 a Dutch trader named De Roy and his
wife settled on the upper Rupunnni, near to what is now Dada-nawa. Ham-
mocks and other articles of aboriginal handicraft, together with local birds and
animals, which the natives are adept at rearing as pets, were purchased in
exchange for salt, knives, fish hooks, etc., and disposed of on the coast. De Roy
also introduced cattle into this part of the Rupunnni by the purchase of some
three or four head from Brazil for milking purposes.

Twenty years after De Roy’s arrival, Melville, who played a great part in
the development of the District, penetrated to the Upper Rupunnni in search of
gold. Finding the life of a trader more congenial, he settled in the District and
also purchased a few head of cattle from Brazil, together with several horses.

De Roy and his wife died towards the close of the last century and Melville
bought up' his entire estate, including one hundred and twenty head of cattle,
the increase from the original three or four. Including these, Melville’s total
purchases of cattle mounted to some three hundred head, and the majority of
the cattle now in the Rupunnni come from this one small herd of &rub stock,
with little or no introduction of fresh or improved blood.

Melville was a man of extraordinary personality and energy, but he had
been bred a townsman and had only very elementary knowledge of aniiR$l

232 AGBIOtLTtJBAt. JOUBBAt OF BRITISH GHUHA, [IX, 4.

husbandry. The result was that h« left the care of his cattle under the supervi-
sion of a few Aboriginal Indians, who had learned a little of the local methods
of handling stock in Brazil, where ranching, although conducted on very crude
lines, was becoming an industry of some importance. As in every country
blessed with natural feed, an ample rainfall and a complete freedom from
disease, Melville’s cattle throve without care and increased at a rapid rate.

There being no overland communication with the coast, all trade was with
Brazil. Manaos was fast becoming an important entrepot and port for the robber
and Brazil nut trade of the Amazon, and at the beginning of the century, Melville
was exporting a few steors there, through the medium of Brazilian friends. His
cattle roamed the range entirely without care, except for an annual round-up for
branding, and as they increased and spread further afield, even this was omitted.
No castrations were done under five years of ago : hence there could be little
selection of bulls. In-breeding was rampant) and progressive, and the methods
of handling crude in the extreme. Cattle were becoming extremely wild and
difficult to round up, in fact only those in close proximity to Melville’s residence
at Dada-nawa were under control. These methods were continued np to, and
even after, the time when Melville was able to sell out to a company, and even
with the advent of fresh settlers, economic conditions have militated against any
great improvement on these original methods of stock management.

The standard coin of Brazil is the milreis which in the early j ears of the
present century had an exehange value of approximately one shilling. The steers
from the Rupnnnni had a splendid reputation for size and quality, directly
attributable to the fact that the country was still understocked. Standard steers
were freely bought on the spot by Brazilian buyers for one hnndred milreis
(five pounds) and selected steers would run to one hundred and fifty milreis.

Export of steers from the Rupnnnni to Manaos was always difficult. The
state laws forbade it and everything depended on the activity or cupidity of the
particular officials in office. Sales becoming increasingly difficult, Melville
approached the Government of British Gniana in 1917 with the project of cutting
a trail to connect the savannahs with the steamer terminus on the Berbice River.

The proposal was a timely one, as the course of the Great War, which had
been in progress some three years, was responsible for inflated prices and a food
shortage, and the project was approved by Government. The construction of
the trail was placed in Melville’s hands, and towards the end of the year 1919 a
few selected tame animals were driven to the coast and the trail declared open.

As a result of this, the Rupnnuni Development Co., Ltd. was floated,
acquired Melville’s cattle interests in the Rnpununi, and bought out two of the
four small Brazilian ranchers who had been allowed to settle on the British side
of the border. In addition, a few individual settlers started ranching.

Wien, however, attempts were made to drive down herds of the ordinary
wild range cattle, it was found that the trail was a cattle trail in name only, and
lacked every facility for the driving of Btock. Actually, the trail r at this period

Plate XVII.

Fia. 2— Crossbred Zebu Hereford Heifei (J Zobu, j Hereford, 1 Rupununi)

Plate XVIII.

Fic. 4 — Driving a Mixed Herd

A SHORT BISTORT OF THE RUPTTITOIW SAVANNAHS.

233

was nothing more than a clearing out through the forest with all trees over four
inches in diameter loft standing. Clearings for grazing, and paddocks or corrals
for holding the cattle at night, were non-existent. High creek banks weie un-
graded, and the swamps, lacking corduroys, were well-nigh impassable. Rest
houses there were none, and the trail proved a ‘via dolorosa’ for both man and
beast, so that for the first two years the losses incurred in driving cattle through
it were terrible.

The Rupununi Development Co., Ltd. now owns the larger part of the stock
in the Rupununi and therefore a short account of its development will not be
out of place. Towards the end of the Great War and in the early post-war years
a wave of speculation swept the Colony. Sugar— the staple industry — was
booming, and it was only natural that the opening up of what was considered to be
a rich and undeveloped stock-raising country should be expected to result in
added prosperity.

Floated towards the ond of llUH, the properties acquired by the Rupununi
Development Co., Ltd. were purchased at a figure far above their actual value.
The main property , Dada-nawa, was a ranch in name only. Equipment, fences,
corrals, etc., were non-existent. Thero were some 15,000 head of scrub cattle of
which a few only could be termed domesticated, the remainder being
little better than wild animals. Despite the fact that there was talk of raising
cattle by the hundreds of thousands, overstocking was already in evidence in
some places (though large areas of course were still entirely unstocked) and
numbers of cattle were of poor conformation, stunted and in wretched condition.
Little notice had as yet been taken of the warning of Professor Ilarriaon,
Director ol Science and Agriculture, that nving to the lack of essential minerals
and the sterility of much of the soil, the number of cattle that the savannahs
could support was limited. IIo estimated one animal to twenty acres, although
an overall average of one to thirty acres iv ould now be nearer the mark.

Amply provided with working capital, the policy should have been to devote
the first year at least to organizing and equipping th<‘ ranches, and perfecting
a system of driving the herds through the newly opened and as yet untested
trail. Unfortunately, owing to lack of knowledge of conditions up-country
an exactly opposite policy was adopted. Hords of cattle were, without prepara-
tion or organization, rushed away from the ranches, the majority to be lost in
the roughly cut cattle trail. But the post-war slump bad already set in, live-
stock values were dropping and all other activities were neglected in an
attempt to bring large numbers of cattle to the coast.

By jho latter part of 1921 the Company’s position already seemed hopeless.
Almost the entire working capital had disappeared and but few steers had
arrived on the coast tor sale. Nothing had as yet been done towards the
development of the ranches. Actually, they were in the same condition as when
pnrohased, except that the best of the steers had already been removed, the
majority to be lost in transit to the coast. A reorganization was obviously
essential and this was carried out, the Company narrowly avoiding liquidation
and being lefbfinancially crippled.

234 AGRICULTURAL JOURNAL OF BRITISH GUIANA, [IX, 4 ,

The second phase consisted of a long nphill struggle without reserves and
against a constant drop in livestock prices which continued until 1936. During
this period, everything possible was done to develop the ranches, but economic
conditions limited the progress made. Pure bred bulls were imported, scores
of miles of fencing constructed, numerous out-stations built and tho cattle brought
under control. Improvements could only be carried out when livestock prices
allowed of a working profit being made, and during this second phase all such
profits were put back into the properties. Progress has, however, been slow and
the quality of the stook still leaves much to be desired.

So much for the Company. The history of the small settler has been
even more unfortunate, and those not possessing some alternative source of
revenue, such as balata bleeding, were in many cases reduced to a state of dire
poverty. At one period, ranchers were driving their cattle to the coast to sell
for $10 per head and of this amount $1.50 was paid for trail toll and over $3
in freight from the terminus of the trail to Georgetown. It was felt by them
that although for years the cry had been to settle the interior, and the Rupununi
District was the only part of the far interior where settlers, the majority
Europeans, lived, worked and brought up their families, yet their pioneering
problems were either completely ignored or treated with scant sympathy. In
an area of several thousand square miles with a resident population of at least
four thousand there is still no medical service and only one small mission
school for Aboriginal Indian children.

Under these conditions, the small rancher has done little or nothing
towards improving his stock. For some considerable period in fact he entirely
discontinued driving his cattle to the coast, as the price obtained barely covered
the expensos incurred between ranch and market.

The main reason for his economic troubles, apart from the difficulties of
communication, is the poor quality of his stock. He in caught in a vicious
circle, since his poor quality cattle bring low prices, and these allow of no
surplus to be expended on the improvement of stock. lie has been blamed for
being unprogresbive, but the fault is not entirely his. It is possible that if
Government, when opening tho cattle trail, had started a small stock farm in
the District for the purpose of breeding improved beef type bulls for sale to
the settlers, there would now he a different tale to tell. Settlers who were in
no position financially to import their own pure bred bulls into the District
would undoubtedly have purchased cross breds on the spot had they been
available.

In the early days, stock in tho Rupununi was entirely free from disease, but
the same cannot be said to-day. A veterinary surgeon permanently stationed in
the District is needed, or failing this, a lengthy visit by a properly equipped
veterinary expedition definitely to establish tho naturo of the stock diseases
now prevalent in the District, and advise settlers on the methods of combating
them,

A SHORT HISTORY OF THE RUPTJHTJNI SAYAJWAHS,

235

The idea that the Rupununi District is a rich stock-raising area capable of
holding hundreds of thousands of head of cattle is a fallacy. Although certain
areas are still capable of holding more cattle, large areas are already heavily
overstocked, and this mainly accounts for the extremely poor quality of much
of the stook.

The soil of the Rupununi savannahs consists of two main types. In the
first place, there is the sandy soil of the high lands and low hills and ridges,
which Professor Harrison described as being 4 barren to sterile*, and it has
been proved that the coarse tuft grass growing on these areas is markedly
deficient in minerals and of practically no feed value. Cattle will only graze
this grass whon it is springing up soft and green after burning, or when forced
to by lack of pasturage on the low ground.

Secondly, thero is the clay soil of the flats and low ground which mostly
lies along the creeks and rivers. These flats flood over for short periods during
the wet season and receive deposits of alluvium. Much of this soil is of well
marked fertility, and although deficient in essential minerals , produces herbage
of definite nutritive value on which cattle thrive . It may here be noted that
the feeding of artificials to the stock to make up for tho marked mineral
deficiency in all types of grazing is, under present conditions, almost out of the
question owing to the extremely high cost of transportation from the coast.

For all practical purposes, therefore, the grazing on the high lands can be
regarded as of little or no value. This means that the number of cattle that
can bo carried on any given area is limited by the extent of tho low lands.
Certain areas are almost totally deficient of good pasturage, and it is tho absence
of cattle in these areas that gives rise to the reports that the savannahs are still
very much understocked.

Taken as a whole, the grazing which is of value does not comprise a fifth of
the entire area. When a range is xmderstocked, the cattle graze in the most
favourable swamps only, and as a rule are in splendid condition. Once tho
economic stocking-up point in numbers is passed, however, these good grazing
areas become denuded of grass, and eventually semi-starvation forces the cattle
to graze on the coarse grass of the high lands. When this occurs, the stock be-
comes miserable in tho extreme both as regards size, conformation and condition.

To, sum up, tho Rupununi savannahs in the writer’s opinion can produce
some five thousand head of marketable steers per annum together with a
proportionate number of spayed females. Owing to the sparseness of the
grazing, the open range system is the only economic method of running the
main herds, but fencing is essential for tho purpose of breeding vfp small herds
of improved stock to provide bulls for the open range. Adequate fencing,
better bulls and proper range control can eventually produce good quality beef
cattle, both for the local market and the West Indian export trade. Breeding

236 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 4.

experiments by the Rupununi Development Co. Ltd. favour a Hereford-Zeba
cross, and grazing tests show that not more than an average of one animal to
thirty acres should be carried.

Primitive methods of stock management, enforced by economic conditions,
and inbreeding have undoubtedly had an adverse effect ; but overstocking is the
main factor in the deterioration of much of the stock in the Rupununi District.
Overstocking on the open range can most effectively be overcome by spaying
heifers, and this practice allows ot the selection of the females to be retained for
breeding and of turning scrub heifers iuto marketable beef animals. The spaying
of all undesirable heifers from overstocked country, and a percentage of the poor-
er animals from stocked up areas, is now a matter of routine on the Rupununi
Development Co’s, main station, but has still to be introduced by other owners.

DAMAGE CAUSED TO RUM PUNCHEONS BY BORING

BEETLES.

L. D. CLEARE, f.r knt.s.,

Entomologist,

Department of Agriculture, British Guiana.

]. Introdnrtio i,

II. Damage to new staves

III. Damage to ‘grogged’ puncheons,

IV. Examination of damaged staves.

(,t) Staves from puncheons in
the Colony.

(b) Staves from puncheons returned
from London.

V Dunnage u ood.

VI. Conclusions and recommendations.

I. Introduction.

The investigation dealt with here was undertaken between November 1037
and January 1938 and was the direct outcome of a complaint received of damage
liy boring beetles to the puncheons of a shipment of rum made to London from
British Guiana in August 1937.

The shipment of rum concerned comprised 141 puncheons from two sugar
factories and was reported as having, on arrival at London, 7G puncheons
(54 per cent.) bored by beetles so that repairs were necessary to the puncheons in
London. The report showed that in the 7<i puncheons there were 173 bored staves.

The puncheons were made at Georgetown, the staves being imported from
the United States of America.

From the first it was evident that there might be difficulty in forming a defi-
nite opinion as to where the damage to the puncheons in question had taken place,
for it was possible that the attack might have occurred at many points between the
receipt of the staves at Georgetown and the final arrival of the packages in
London. This was further added to by the absence, at the beginning, of the
damaged puncheons so that a more extensive enquiry had to be undertaken than
perhaps would have been necessary otherwise.

II. Damade to New Staves.

An, examination was made first of new staves, and stacks of staves at the
cooperage wharf at Georgetown of varying dates of arrival were examined, while
on 9th November a new shipment of headers was received and these latter were
examined both at the time of their arrival and also a few days afterwards.

At the outset it must be stated that both such staves and headers showed
damage which was evidently the resalt of beetle attacks, and judging from the
borings in the wood had been caused by probably at least three different species
of inseots. In spite of this no boring beetles were found and it was evident that
the damage had occurred some time previously.

238 AGRICULTURAL JOURNAL OF BRITISH GUIANA- flX. 4.

This damage was not excessive and amounted to 6.7 per cent, over the three
lota examined. The details of these examinations are as tinder :

Lot

No.

Date of
examination

Material

Ship.

No. ex-
amined

No.

bored

Per oent.
bored

16.xi.37.

Headers

88.

10.xi.37.
(Brown spot)

571

6.2

17.xi.37.

Staves

ss.

13.x. 37.
(Grey spot)

370

9,7

III

17.xi 37.

Headers

tlSvii.37.
(Green spot)

-11C

- —

3.8

The damage in both staves and headers was usually quite noticeable and in
many instanoes it was obvious that should such material be used in packages it
would cause leakage.

In staves with the smallest sized holes it was not apparent at first whether
these were capable of causing leakage. Careful examinations were made,
therefore, of a number of these borings by splitting and sectioning the staves,
and in several instances it was found that even these holes of small diameter
had gone through the staves.

In the headers the damage, usually a larger-sized hole, invariably took the
form of an oblique boring at the edge of the particular piece of wood, and here
again it was obvious that should such material be built into a package there was
likelihood of leakage resulting therefrom.

III. Damage to ‘Grogged* Puncheons.*

It has long been known amongst coopers in the Colony that puncheons which
have been “skipped” and “grogged” when stored for a time, either before or
after being repaired, develop “worms” which will in time cause leaks, and these
worms may occur to such an extent as to cause the package to be discarded.

The staves of these packages in the course of their storage with rum prior to
skipping become soaked with the liquor, and in spite of the grogging still rotain
some of the alcohol in the wood. When water is placed in these puncheons sub-
sequently some of this alcohol is drawn from the wood, a fermenation is set up
and beetles are attracted.

Samples of water from grogged puncheons both at the Colonial Bond and at
the cooperage were obtained and the alcoholic content determined. The figures
in this connexion are given in Table I.

•Wbe* runi puncheons have been in bond for some time defects in the puncheons such as
broken staves necessitate a certain number of the packages being changed, the rum being
transferred to other pundjeons ; this process is known as “skipping”.

“ Skipping ” having taken place the old package is then ^grogged” t\e M water put in and
retained for a period and then thrown away, 1 *

Table I.— Alcoholic Contest of Water from Grogged Puncheons

bAliAGE CAUSED TO RUli PUNCHEONS BY BOEING BEETLES. £30

I a

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240

AGRIC GTLTUR AL JOURNAL OF BRITISH GUIANA.

Dot. 4.

A few such “grogged" puncheons were examined, and by carefully
sectioning staves from one of these infested puncheons some of the beetles which
were attacking them were secured. These beetles proved on examination to be
a species of Xylebotm , which genus is well known as wood borers.

The attack in such puncheons often occurs in the headers or around the
groove where the header fits into the staves, but also in the staves themselves
about the central area where ihe puncheon comes in contact with the ground
when stored on its side. In most instances seen where the attack occurred about
the centre of the stave it could be associated with some injury to the stave,
sometimes only a small indentation, which had allowed ingress of the beetle.

When the damage occurs in the headers, or in their immediate vicinity, the
groove, a leak is readily formed, as may also occur if the damage is between two
staves. When a stave is penetrated directly, however, the entrance of the beetle
in itself may not result in leakage, for in such instances, the beetle, or its larva,
does not penetrate beyond a point in the wood where it becomes more or less
soaked with the contained spirit. Under such conditions, where leakage occurs
it is invariably associated with cracks in the wood offen brought about by
extreme heating, and the resulting burning and cracking, in the process of
making the puncheon.

IV. Examination of Staves from Damaged Puncheons.

A number of staves removed from puncheons which showed beetle borings
were examined comprising (a) staves from puncheons in the Colony and (b)
staves from puncheons returned from London around which this enquiry started.
These will be dealt with separately.

(a) Staves Jrom puncheons in the Colony. A number of puncheons which
had been shipped to a plantation from the cooperage in the latter part of
November, were reported on arrival at the factory to be bored, and later when
the damaged staves from these puncheons were removed and returned to George-
town they were examined.

These puncheons were made at Georgetown in October and shipped from
Georgetown between the 27th and 2!Uh October, and on fith or 7th November,
while at the sugar factory, they were observed to be bored. The shipment
comprised 100 puncheons, and 30 of these showed "worm holes" in some of their
staves, Twenty-eight of these damaged staves, and three header-pieces
were received at Georgetown on 15th December, sent to this laboratory on the
following day, and examined on 17th December. Of these staves eighteen
were found to be damaged sufficiently to cause leakage, it is believed, and, in ten
staves, it was not possible to be certain whether the damage was of such a
nature as to cause leakage.

The detailed results of this examination are given in Table II.

DAMAGE CAUSED TO RUM PUNCHEONS B* BORING BEETLES. 241

Table II.— Examination of Damaged Staves from Puncheons
Ex-shipment of 27th/29th October, 1937.

Group.

Number of Holes.

Outer side
of staves
only

Inner

side

only

Extending through j
staves

Total

Plugged

Not plugged

A — 18 staves
damage in which
would cause
leakage

' 9

(1)

, 124

B— 10 staves
damage may
cause leakage

(2)

All of this damage had evidently occurred some time previously, and, in
Borne instances at least, before the packages were constructed and was the same
as that occurring in new imported staves.

(b) Staves from puncheons returned from London. Late in December six
puncheons were received at Georgetown from London which puncheons were
stated to be part of the consignment complained about and to be damaged by
beetle borers.

On arrival these puncheons were seen and beetle borings were quite
apparent in all, even on very cursory examination.

At a later date, careful examinations of these packages were carried out, and
the results of the examinations are given below.

The marks on these puncheons showed that they were the product of two
oooperages in Georgetown, and were as follows :

(') In Group A of a total of 121 holes, 22 were situated under the bands of the puucheone,
of which 10 had been plugged and 3 not plugged.

( J ) In Group B of the 16 holes showing on the outer side of the stives, G were only
Burfaoe holes aud had been plugged.

fAftl-B ill. — il-ARKS ON jPtm0HBON& fesAlfafttito.

•it — i

Puncheon

Estate Marks
(Stencilled on
top)

Colonial Bond
Marks
(scribed)

Colonial Bond Details*

1936

13 Oct., 1936

Pin.—

5161

Mark — A. 92 puncheons

616

Tare 176 lb.
100 gals.

coloured rum

— —

~ _ - — ~ —

1935

262

13 Feby., 1935

Pin.—

Mark— ^AS^.

GO puncheons coloured rum

1936

lil

Ifa Bond 9 April 1936

6 Hogshead ^MAS ^ (Pin. — )

G, 1

1590/95 |

T. 1.2.25.
(other marks

1935

_ Cooperage)

Racked into 3 puncheons

30 July 1937

/ r \ R1 — 3 shipped
1590795"

ss. 4 Aug. 1937

1935

1,320

5 April 1935

Pirn-

<A> !

35 !

Mark — KF (?) M. 28 puncheons

492

coloured Rum

1937

4275

4 Aug. 1937

Pin.—

ccc

297 |

T. 1.3.7

;

Mark CCC. 59 puncheons
coloured rum

5173

Date as in Puncheon A

4 >

628

1936

Tare 184 lb.

; 100 gals.

above

DAMAGE CAUSED TO BUM PUNCHEONS B * BOBING BEETLES. 243

Both the Colonial Bond and the estate marks on the packages showed that
only one of the six packages contained 1037 ram. The other five contained
either 1935 or 1936 ram. Although the package “ C ” contained 1036 rum. the
liqnor was placed in it only in Jnly 1037, bat th package itself was evidently
constructed in 1935 and had apparently been need at some time previously to the
oooasion of the last shipment. All the packages, with the possible exception of
“ C," had been in the Colonial Bond for some time prior to shipment, one since
February 1935 (B), another sinoe April 1935 (D) and a third sinoe October 1936 (A).

The borings in these puncheons were located almost entirely towards the
ends of the puncheons, that is, where the puncheons tapered and not about the
middle and greatest girth, and staves in all positions in the pnncheons were
found to be bored.

Further examination of the borings themselves showed that the majority
did not extend for any depth into the staves and in fact many were only surface
borings. Those which penetrated the staves did so always across the grain of the
wood and often in a diagonal direction coming out on the sides of the staves
where they were in contact with the adjacent staves, and invariably did not go
beyond a point in the wood where it became sodden with the contained alcohol.
Some of the borjng commenced at a point where two staves abutted and where
there was a slight indentation which allowed ingress of the beetle.

In two instances at least when a puncheon was broken down it was observed
that between two staves there still existed the “ flag ” (made of the fibre from
plantain psendostem) which had been placed there in the coopering of the pack-
age in order to make a tight joint. And what was especially important was that
those “flags’ 1 had been penetrated by beetle borings.

No such borings of the “ flags” could have existed before they were put in
place in the packages and the fact that the borings of the flags and of the staves
coincided and were identical in every respect loft no doubt of their having
occurred at a later date.

In another instance there was found a hoop to which wood fibres were
adhering, and the area of the staves immediately adjacent to this was severely
bored.

A very carefol and detailed examination was made then of a number of
Individual, staves, and dissection of boring carried out. Staves from each of the
five punoheons were thus examined. In this way, in staves from each package
beetles were obtained which had died in their borings and which on examination
proved to belong to the genus Xykborus.

•

As regards these puncheons from London* then* the facts pointed to the
damage having occurred after the filling of the packages* and also after their
removal from the Colonial Bond, and indeed, suggested that the damsge had
occurred in transit,

244

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[IX, 4.

V. Dunnage Wood.

Suspicion fell upon the dunnage -wood used in storing the puncheons on
shipboard. Accordingly, a stack of this dunnage in the vicinity of the cooperage
and shipping wharf was examined.

This dnnnage is comprised of a miscellaneous collection of local wood,
among which examples of Congo Pomp, ( Cecropia spp.) Hog Plum ( Spondias
Monbin L.) and Shiroua, ( Nectandra 8pp.) were seen.

Ample evidence was soon obtained that some of this wood was severely
attacked by beetles, and further examination disclosed that beetles of the genus
Xyleborus constituted the majority of these insects.

In this material the Xyleborus attack was at the time of my examination still
active and there was little difficulty of obtaining live beetles although it was
evident that the stack had been in position for some weeks.

VI, Conclusions and Recommendations.

From what has been stated above under the different sections it will be seen
that beetle damage as found in the present investigation falls into two distinct
categories, namely (i) that occurring in new staves, and (ii) that occurring in
puncheons in one form or another.

(i) Damage occurring in new staves. Little need be said as regards this.
It has been stated already that it is the result of beetle attacks before the arrival
of the staveB in the Colony, and probably occurred at the point of logging
operations. Sufficient it is not active when the staves are received in British
Quiana, and as the percentage of staves damaged is not high the allowance made
by the suppliers (1 ,200 staves are given per mille rate) is ample to allow for
rejections arising from this cause. Incorporation of staves damaged in this
manner into puncheons, as previously pointed out, would in many instances
cause leakage.

(ii) Damage occurring in puncheons. In grogged puncheons which were
in storage and in the puncheons returned from London, as has been stated
previously, Xyleborus beetles were found to be the cause of the damage.

Beetles of the genus Xyleborus are well known as timber borers in different
parts of the world. On account of their habit of feeding on certain fungi which
grow in the tunnels which they make in the wood an essential for their exis-
tence is that the wood whioh they bore must be at least moist 1 , and conversely
one of the characteristics of these beetles is that they do not attack dried and
Reasoned wood.

Accordingly, normally it would not be expected that these beetles would
attack rum puncheons. If, however, the exterior of a puncheon, either empty,
artly filled with weak alcoholic solution or even with nun itself, is wet for

DAMAGE CAUSED TO RUM PUNCHEONS BY BORING BEETLES. S45

gome time, or oomes in direct with some substance itself more or less wet over a
period of time long enough to allow the wood of the puncheon to take up
moisture such a puncheon might be attacked by Xyleborm beetles.

The damage caused to grogged puncheons was not investigated in the
present instance beyond the point of establishing such damage and ascertaining
the insect concerned.

As regards the puncheons returned from London, the fact that the attack
was not seen when it first occurred and in an active state, and that several weeks
had elapsed before the packages were examined, any conclusions arrived at in
this connection must necessarily be of a circumstantial nature.

With this reservation then, it may be said that as the result of investigations
and the conditions observed, and the examinations made of the puncheons,
there is reason to believe that the damage to these puncheons occurred after the
packages were removed from the Colonial Bond, and in all probability while
they were in transit to London. Further, that such damage was caused by
Xylrborus beetles ( Xyleborm badius Eich. Det. K. E. Schedl, through Imperial
Institute of Entomology, London) some of which were found in the borings in
the puncheons; that such beetles were breeding in all probability in the dunnage
wood used with this shipment of rum and that the puncheons were infested and
damaged by such beetles.

The measures to be adopted with regard to damage to puncheons in
transit and arising from the dunnage wood is, of course, a change in the material
used as dunnage. In this connection, it was suggested that perhaps wallaba
{.Eyerua spp.) “ ton-wood ” might be used instead of the present miscellaneous
“cord-wood.” This is not recommenced as the sapwood of wallaba also has
been observed to be attacked by several spe cies of Xyleborm beetles.

SUMMARY OF AGRICULTURAL LEGISLATION IN
BRITISH GUIANA.

INDEX.

Part I.

GENERAL AND MISCELLANEOUS AGRICULTURAL LEGISLATION,

Agriculture — General.

The Board of Agriculture Ordinance , No. 26 of 1934.

The Crops and Livestock Registration Ordinance, No. 22 of 1917, (Cap. 159).

The Crown Lands Regulations 1919, made under section 11 of the Ct'own
Lands Ordinance, No. 32 of 1903, (Cap. 171).

The Lands d Mines and Forestry Department Ordinances related to Agriculture:

The Lands Mines Department Oidmance, No. 31 of 1903,
(Cap. ICG).

The Land Surveyors Ordinance, No. 20 of 1891, (Cap. 167).

The District Lands Partition and Re-allotment Ordinance, No
16 of 1926, (Cap. 169).

The Crown Lands Ordinance , No. 32 of 1903, (Cap. 171).

The Ciown Lands Resumption Ordinance, No. 30 of 1905,
(Cap. 172).

The Polder Ordinance, No. 25 of 1910, (Cap. 174).

The Forestry Ordinance, No. 29 of 1927, (Cap, 176),

Sugar.

The Sugar Experiment Stations Ordinance, No. S3 of 1937.

The Sugar (Regulation of Prices) Ordinance, No. 15 of 1930.

The Sugar ( Temporary ) Excise Duty Ordinance, No. 2 of 1932 amended ly the
Sugar (Temporary) Excise Duty ( Amendment ) Ordinance, No. 5 of 1987.

The Sugar (Temporary) Excise Duty Regulations , 1932 .

Tlfo Sugar Quota Ordinance, No. 19 of 1937.

The Molasses (Disposal) Ordinance, No. 28 of 1981.

The Molasses (Disposal) Ordinance, No. 41 of 1983, •

StfjfMARY OF AGRICULTURAL LEGISLATION IN BRITISH GUIANA 24 f

Bice.

The Rice (Export Grading) Ordinance, No, 18 of 1930 amended by the Bice
( Exjtort Grading ) Ordinance, No. 40 of 1932.

The Rice ( Export Blending and Grading ) Regulations, 1934 amended by the
Rice (Exjiort Blending and Grading) Regulations (No. 3), 1934.

The Rice (Exjwrt Trade ) Ordinance, No. 17 of 1935.

The Rice (Export Trade) Regulations, 1935.

The Rice Factories Ordinance, No. 26 of 1933.

The Rice Factories Rules, 1934.

Coconuts.

The Coconut Products ( Control ) Ordinance, No. 36 of 1935.

The Coconut Products Rules, 1936.

Narcotics.

The Tobacco Cultivation (Repeat) Ordinance, No. 4 of 1930.

The Indian Hemp and Datura Ordinance, No. 36 of 1924, (Cap. 190).

The Opium Ordinance, No. 13 of 1926, (Cap. 191).

Agricultural Credit.

The Plantation (Proprietors) Government Loans Ordinance, No. 9 ot 1893,
(Cap. 158).

The Agricultural Relief Ordinance, No. 20 of 1896, (Cap. 152).

The Rice Growers Loans Ordinance, No. 2 of 1922 (Cap. 155).

The Co-ojK’rativc Credit Banks Ordinance, No, 28 of 1933.

The Co-operative Credit Banks Regulations, 1933.

The Co-operative Credit Banlcs Regulations, 1937.

The Co-ojierative Credit Banlcs (Amendment) Ordinance, No. 13 of 1938.

Miscellaneous,

The Public Gardens and Agricultural Shows Ordinance, No. 34 of 1935.

The Government Botanic Gardens Regulations , 1936.

248

AGRICULTURAL JOURNAL OP BRITISH GUIAltA.

flX, 4.

PART II.

LEGISLATION RELATING TO INSECT PESTS AND FUNGUS DISEASES.

The Plant Diseases & Pests { Prevention ) Ordinance , No. 37 of 1935.

(A) Regulations and Orders Relating to Pests and Diseases
Present in the Colony.

The Plant Diseases and Pests ( Notification) Regulations, 1936.

Order re Coconut Caterpillar { Brassolis sophorae L.) and Witch Broom ( Maras-
mius p erniciosus Stahel).

(B) Orders and Notices Relating to the Importation and
Exportation of Plants, Fruit, Seed, etc.

Sugar Canes, Grasses, Soil, Banana and Plantain Suckers. Order re
importation of,

Plants, seeds, etc. Order re examination of,

Mediterranean Fruit Fly ( Ceratitis cupitata). Orders to prevent intro-
duction of

Citrus. Orders prohibiting importation of from United States of America and
West' Indian Islands.

Raw Coffee. Order prohibiting importation of.

Pimento. Order prohibiting importation of, from Jamaica,

Padi. Order prohibiting importation of,

Part III.

LEGISLATION RELATING TO LIVESTOCK, BEES AND WILD BIRDS.

Livestock— General.

Pounds Ordinance, No. 1 of 1866, {Cap. 93).

Pound Fees Rules and Regulations, 1937.

Cattle Stealing Prevention Ordinance, No. 3 of 1877, {Cap. 91).

Cattle Trail ( Tolls) Ordinance, No. 16 of 1929.

Cattle Foods. Notice re Importation of,

Veterinary.

The Animals Diseases Ordinance, No. 29 of 1936.

The Animals Diseases Regulations, 1937.

Importation of Animals. Order re,

Beer.

The Importation of Bees Ordinance, No. 38 oj 1935.

The Importation of Bees Regulations, 1936,

The' Importation of Bees {Amendment) Ordinance, No. 18 of 1936.

Wild Birds.

The Wildr Birds Protection Ordinance, No. 81 of 1919, {Cap, 278),

A SUMMARY OF AGRICULTURAL LEGISLATION IN
BRITISH GUIANA.

Part I.

GENERAL AND MISCELLANEOUS AGRICULTURAL

LEGISLATION.

AGRICULTURE— GENERAL.

The Board of Agriculture Ordinance , No. 26 of 1934.

Under this Ordinance there is established an advisory Board of Agricnltnre
consisting of the Director of Agriculture who shall be Chairman, the Deputy
Director of Agriculture who shall be Vice-Chairman and not more than seven
other persons who shall be appointed by the Governor. Every appointed
member shall hold office for three years, but shall be eligible for re-appointment.
The Governor may appoint some person to be a member in place of an appointed
member who is absent on leave (which may be granted by the Governor) or
owing to death or other cause. The Board shall meet at least onoe every three
months, or at any time at the request, in writing, of three members Btating the
purpose for which the meeting is required.

Under this Ordinance the Board of Agriculture Ordinance, No. 27 of 1920,
(Cap. 150) is repealed.

The Crojis and Livestock Registration Ordinance , No. 22 of 1917, (Cap. 159).

By this Ordinance the occupier of any land or the owner of any live-
stock is required to give, before the last day of January of each year, returns
on the approved forms showing the acreage of land under cultivation at the
date of the return, and the crops and produce thereof reaped during the year
ending on that date, also the number of animals kept at the date of the return,
and their increase during the year ending on that date.

The Crown Lands Regulations 1919, made under section 17 of the Croton
Lands Ordinance, No. 32 of 1903 , (Cap. 171) contain a number of regulations
concerning Agriculture.

Part I deals with Applications for Grants or Leases, Licences or Permissions
of Crown Lands and the Renewal, Revision, Transfer, etc., of the same. Part
II is concerned with surveys, where such are required, and Part IV deals with
Grants to small cultivators.

&)6 AGRICULTURAL JOURNAL OF BRITISH GUlANA. [iX, L

Part V covers leases both for agricultural purposes and for grazing purposes,
and Part VI deals with Permission for Grazing Areas in the interior.

Part VIII embraces Leases and Licences to cut wood and Part IX Lioenoes
to collect Balata and Gums, etc. Regulations 70 and 71 et scq in this latter part
prescribe for the collection of Orchids and other Forest Products such as
Haiari (Lonchocarpw spp.), Tonka Beans, etc., for which permission has to be
obtained from the Commissioner of Lands and Mines.

Part X, Regulations 80 et scq deal with the removal of sand or shell from
Crown Lands.

LANDS AND MINES AND FORESTRY DEPARTMENT ORDINANCES RELATED

TO AGRICULTURE.

The following Ordinances may under certain circumstances concern the
Department of Agriculture.

The Lands and Mines Department Ordinance, No. 81 of 1903, ( Cap. 1GG)
makes provisions as to Crown and Colony Lands. 'The Land Surveyors
Ordinance, No. 20 of 1891, (Cap, 167) covers the making of surveys, and the
District Lands Partition and lie-allotment Ordinance, No 1G. of 1920, (Cap. 169)
conoerns the partitioning and re-allotment of land.

The Crown Lands Ordinance, No. 32 of 1903, (Cap. 171) deals with the
leasing, etc., of Crown Lands, and contains (section 17 (f>) ) Regulations as to the
Rupununi Cattle Trail and the payment of Tolls thereon. Further regulations
made under this Ordinance have been dealt with above in the section concerning
the Grown Lands Regulations, 1919.

The Crown Lands licsump/ion Ordinance, No. 80 of 1906, (Cap. 172) deals
with land which has been abandoned for more than 8 years, and the ownerB of
which are called upon to prefer their claims, and The Polder Ordinance, No. 25
Of 1910, (Cap. 174) deals with the creation of Polders.

The Forestry Ordinance, No. 29 of 1927, (Cap. 176) covers the demarcation
and regulation of Forest Reserve areas, and the unlawful possession of Forest
Produce.

SUGAR.

The Suyar Experiment Stations Ordinance, No. 33 cf 1937.

This Ordinance makes provision for a Committee, consisting of six persons
immediately connected with the Sugar Industry, together with the Director of
Agriculture as Chairman, to maintain and manage such Sugar Experiment
Stations as may be deemed necessary, and to appoint such executive officers as
maj^ba required. Expenses shall be paid out of a Sugar Experiment Stations
Fund and a rate calculated on the acreage of land under sugar cane cultivation is
levied on the Sugar Plantations, 60 per cent, of the amount due being payable on or

A SUMMARY OF AGRICULTURAL LEGISLATION IN BRITISH GUIANA. 251

before January 31 and 40 per cent, on or before June 30. Where investigation of
an extraordinary nature becomes necessary, an additional rate may be levied.
The Committee may make regulations, subject to the approval of the Governor*
in-Council, to carry out the provisions of the Ordinance.

Under this Ordinance the previous Sugar Experiment Stations Ordinances
No. 41 of 1932 and Nos. 14 and 31 of 1934 are repealed.

Sugar (Regulation of Prices) Ordinance, No. 15 of 1930.

By this Ordinance the Governor is empowered to fix the maximum price
for which the various grades of sugar manufactured in the Colony may be
retailed.

Sugar ( Temporary ) Excise Duty Ordinance, No. S of 1932 amended by the
Sugar ( Temporary) Excise Duty ( Amendment ) Ordinance, No. 5 of 1937.

These Ordinances impose an excise duty at the rate of 90 cents on every
100 pounds weight of all sugar manufactured in the Colony and sold for home
consumption. The first Ordinance provides for the keeping of the necessary
books by Sugar manufacturers and producers, and limits the price of sugar
liable to duty. It also sets out the method of payment of duty.

Sugar ( Temporary ) Excise Duty Regulations , 1932.

These Regulations, made under the provisions of Section 2 (1) of the Excise
(Regulations) Ordinance, No. 21 of 1903, (Cap. 40) stipulate more fully the
form of books to be kept in accordance with the above Ordinance, (No. 2 of
1932). They also specify that all Sugar manufactured at a factory must be
packed in bags containing either 230 pounds, 125 pounds or 112 pounds of
sugar nett weight.

The Sugar Quota Ordinance, No. 19 of 1937,

This Ordinance restricts and regulates the export of Sugar from the Colony
by tho allocation to local manufacturers of quotas for exportation. Sugar may
only be exported under licence and export certificate.

Molasses ( Disposal ) Ordinance, No. 23 of 1931.

This Ordinance makes it compulsory for any persons disposing of molasses,
except for export from the Colony, to keep a Molasses disposal book in which
must be recorded details of sale. A statement of these sales must be submitted
to the Commissary monthly. No person may sell or receive more than two
gallons without a certificate,

Molclsses ( Disposal ) Ordinance, No. 41 of 1933.

This Ordinance makes it obligatory for any person receiving Molasses,
except for export purposes, to state in Writing the purpose for which he desires
to obtain the molasses. No person may sell or receive more than two gallons of
molasses excgpt there be also provided a certificate of the sale.

252

agricultural journal of British gtjiana.

[IX, 4.

RICE.

The Rice {Export Grading) Ordinance , No. IS of 1930 amended by the Rice
(Exjtort Grading) Ordinance , No. 40 of 1932.

These Ordinances prohibit the export of Rice without inspection and grading
and stipulate that shipments of Rice for export shall be blended so as to ensure
that the contents of each individual container of a consignment are uniform.
Inspectors to enforce these laws are to be appointed by the Director of Agricul-
ture with the approval of the Governor-in-Council. Provision is made for the
appeal to the Director of Agriculture by any aggrieved person against any
decision of an Inspector.

Rice (. Exinjrt Blending and Grading) Regulations , 1934 amended by Rice
( Export Blending and Grading) Regulations {No. 3 ), 1934.

The grades of Rice are described in a schedule attached to the Regulations
and in the amendment. No Rice other than Broken and Super Broken may be
submitted for grading unless it has been previously blrended. No person shall
blend Rioe unless he has first obtained a licence for the purpose from the Director
of Agriculture arfd such licensed blenders shall be registered. A licence ceases
to have effect at the end of every financial year, but may bo renewed for the
ensuing financial year. The Director may, if he considers fit, remove from the
register the name of any blender. The blender’s foe is limited to two cents per
100 pound bag and four cents per bag over 100 pounds. A set of guide samples
according to grades will be supplied by the Department of Agriculture to regis-
tered exporters of Rice. Rice for export shall be delivered at specified wharves
and in new bags. Application for grading must be made to the Inspector not
less than 24 hours prior to shipment. Each application for grading must be
accompanied by the certificate of a registered blender certifying that the Rice has
been blended and must be signed by the Secretary of the Rice marketing Board
before they are delivered to the Inspector. Consignments of Rice must be
pointed out to the Inspector by the owner or his agent on the wharf and the
Inspector shall examine by samples a minimum of 25 per cent, of the bags. The
consignor shall pay a grading fee at the rate of one cent per bag of 100 pounds
or less and at cents per bag of more than 100 pounds. After samples have
been taken from a consignment the exporter shall present his Customs specifica-
tion form, on which is indicated the name of the wharf, to the Inspector for
certification. At the timo of exportation this form shall then be presented
to the wharfinger who will attach a further certificate stating that the Rice
specified is the same as that examined by the Inspector. The specification form
and Wharfinger’s certificate shall be delivered to the Customs Offioer at the time
of shipment. If Rice has been graded and is removed from the place of delivery
without being shipped it must be regraded before export. A grading certificate
remains valid for 14 days ; it may be renewed under the authority of the
Director of Agriculture. The exportation of Rice infected with insect pests or
fungi, or with objectionable odour, is forbidden, and provision is ^made for the

A SUMMARY OF AGRICULTURAL LEGISLATION IN BRITISH GUIANA. 253

removal of each Bice, All Bice exported mast conform to the standards of the
grades described in the Schedule attached to the Regulations and in the
Amendment. Bice intended for special markets 'will not be allowed to be
exported unless it conforms to the requirement of those marketB.

Under these Regulations the Rice (Export Blending and Grading) Regula-
tions, 1932 and 1933 are revoked.

The Rice {Export Trade) Ordinance, No. 17 of 1035.

This Ordinance provides for the establishment of the British Gniana Rice
Marketing Board, a corporate body which may sue and be sued in its corporate
name. The Board is to consist of the following members : —

(a) two officers in the public service appointed by the Governor.

(b) five other persons appointed by the Governor-in-Council.

The Board may, with the approval of the Govemor-in-Council, appoint a
salaried secretary and may employ such other officers and servants as required.
An advisory Committee consisting of six persons shall be appointed by the
Governor-in-Conncil to advise the Board on the price of Rice and on all other
matters in which the Board may seek its advice. The Board may make regulations
to fix the price of Rice, prescribe the form of contract for the sale of Rice, grant,
renew or Buspend exporters’ licences, approve of exporters’ sgentsand generally
take action to improve the Rice Trade. Ihe Board is empowered to collect fees
which are to constitute the revenue of the Board, out of which expenses shall be
defrayed. Specifications are made in regard to the terms of contracts and
and licences to export Rice. No person may export Rice unless he holds the
Board’s licence, nor without the Board’s permission sell Rice at a price below that
fixed by the Board.

The Rice (Export Trade) Ordinances, Nos. 47 of 1932 and 21 of 1933 are
revoked.

Rice {Export Trade) Regulations , 1035.

These Regulations concern the fixing of the prices of export Rice, the grant-
ing of credit to buyers and the remuneration payable to exporters’ agents.
They stipulate the manner in which contract sales may be effected, and provide
for the proper appointment of agents. Every bag of Rice for export shall be
clearly marked with the grade of the Rice therein.

The Rice Factories Ordinance , No. 26 of 1933.

ThiB Ordinance stipulates that before the erection of a Rice factory a
certificate stating that the premises are fit to be used as a Rice Factory, having
regard to public health and sanitation, must be obtained from the proper
authority. After this certificate is obtained, application may then be made to
the Commissioner of the District for a licence for which a fee of $1.00 is payable
and which will expire on the 1st of December of each year. Rice may not be
manufactured except by the holder of such licence. Where a Commissioner has
refused to ggant a licence, appeal may be made to the Governor-in-Council. If

&54 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [iX, 4.

a licence is to be transferred, application in writing most be made by the
transferor and transferee to the Commissioner. The holder of a licence must
keep proper books at the Bice factory showing the quantities of Padi received
and the amounts of Bice mannfactnred and must issue and record receipts for
such Padi. During January and July of each year returns showing the matters
recorded in these books must be made to the Commissioner. For the purpose of
this Ordinance, a bag of Padi and Bice are taken as weighing 143 pounds and 180
pounds gross, respectively.

Authorised persons are empowered to inspect a factory, any Padi or Bice on
hand, or any books kept under this Ordinance. It is prohibited for anyone to
sell, purchase or receive Padi for the manufacture of Rice except at a price
calculated at a bag of 143 pounds gross.

The Bice Factories Buies, 1034.

These rules specify in detail the form of books and receipts to be uBed under
the above Ordinance.

COCONUTS. ,

The Coconut Products ( Control ) Ordinance , No. 36 of 1035.

This Ordinance regulates the manufacture and sale of products obtained
from the kernel of the Coconut.

Part I.

Coconut Products may only be manufactured by a licenced manufacturer
and sold by a licenced broker, the licences to be obtained in each case from the
Commissioner of the District, both costing $5.00, and expiring on December
31 of each year. Where application for a licence is refused, appeal may be
made to the Governor-in-Council, who may also suspend or revoke licences.
Every Copra or Crude Coconut Oil producer shall be registered by the Commis-
sioner of the district, for a fee of 24 cents, and no unregistered person may
produoe Copra or Crude Coconut Oil. Copra may only be sold through or
exported by a broker, and a broker may not sell Copra to any person in the
Colony who is not a manufacturer. The Governor may from time to time
prescribe the percentage of the quantity of Copra under control of a broker
which may be exported during any period of 3 months,

Part II.

A Brokers* Board shall be established consisting of all licensed brokers and
two Copra producers appointed by the Governor-in-Council. A Secretary shall
be appointed and meetings held onoe a week, Charges to defray the expenses
of the Board shall be fixed by the Board, and not exceed 20 oents per ton of
Copra sold. The Board shall at its weekly meetings fix the amonnt to be
advan^pd by brokers to producers in respect of Copra delivered to the brokers,
the amount of this advance being based on the price of Copra as fixed by the
Govemor-in-Council. The brokerage charge shall be at the rate of 25 cents for
100 pounds. of Copra, Proper bqok* shall be kept by brokers showing the

A SUMMARY OP AGRICULTURAL LEGISLATION IN BRITISH GUIANA. 235

purchases and sales of Copra, and quarterly returns made accordingly to the
Commissioner of the district. No person may aot as a broker unless a sum of
$5,000 is deposited with the Colonial Treasurer or a banker’s undertaking given
fop this amount.

Part hi.

The following excise duties shall be levied on Coconut Products manu-
factured and consumed in the Colony, to wit, 12 cents per gallon of deodorized
Coconut Oil and 42 cents per 100 pounds of Lard Substitute. Books shall be
kept by manufacturers of Coconut Products, showing the amount and origin of
produots received and manufactured, and monthly returns made accordingly to
the Commissioner of the district. Producors of Copra and Crude Coconut Oil
shall keep similar books.

Part IV.

No manufacturer may pay less for Copra than the price fixed from time to
time by tho Govemor-in-Council, nor less than an equivalent price for Crude
Coconut Oil, reckoning 100 pounds of Copra = 6§ gallons Coconut Oil, Provision
is made to cover cases in which a manufacturer is also a producer of Copra or
Crude Coconut Oil. Tho Governor may prescribe standards of quality and fix
maximum wholesale and retail prices within the Colony. Crude Coconut Oil
may not be exported except under licence. Provision is made for tho examina-
tion of samples of Crude Coconut Oil and other coconut products by the Govern-
ment Analyst. Authorised persons may inspect factories and brokers’ premises
and examine the books at all reasonable times. No coconut product exceeding
1 gallon or 10 pounds may be removed except by permission of a Commissioner,
who may, however, authorise a manufacturer or rotailer to remove coconut
products from his premises at his own discretion.

Under this Ordinance tho Copra Products (Sale and Manufacture) Ordinan-
ces, Nos. 31 of 1933 and 23 of 1934 are repealed.

The Coconut Products Rules, 1936.

These rules prescribe the form of licences, certificate of registration, register,
books and removal permits called for under the above ordinance.

NARCOTICS.

Tobacco Cultivation ( Repeal ) Ordinance, No. 4 of 1980.

This Ordinance repeals tho Tobacco Cultivation Ordinance, No. 14 of
1912, (Cap. 161) which controlled the cultivation and manufacture of Tobacco.

The Indian Hemp and Datura Ordinance, No. 36 of 1924 and the Opium
Ordinance, No. 18 q) 1926. (Cap. 190 and Cap. 191).*

Under these Ordinances it is unlawful to cultivate the Indian Hemp
( Cannabis sativa or O. indica), Datura ( Datura fastuosa, D. stramonium,
D. motel and their allies) or the Opium Poppy t Papaver somm/erwn),

&56 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 4.

AGRICULTURAL CREDIT.

The Plantation (Proprietors) Government Loans Ordinance, No. 9 of 189S,

(Cap. 158).

This Ordinance gives the right of summary recovery over by one
co-proprietor of a plantation paying Government loan (i.e. loan made from
public moneys under the sanction of the Legislative Council) for another
co-proprietor.

The Agricultural Relief Ordinance , No. 20 of 1896 , {Cap. 152).

This Ordinance creates a preferent crop lien on the crop or crops to be
reaped during the then current year for loans or advances made to the owner of
land (/>., cane plantation and other land cultivated for at least one annual crop)
for maintaining cultivation and management, machinery and buildings, purchase
of supplies and payment of taxes, etc., when recorded in prescribed loim by
the Registrar of Deeds. The lender is exempt from obligation to see to the
application of the loan, and has a right to inspect the crops pledged. Account
must be kept by the owner of the application of the loan. Misapplication of
the loan is de'emed a felony.

The Rtre Groieer^' Loans Ordinance , No. 2 of 192?, (Can. 155).

This Ordinance authorises the Colonial Treasurer to advance out of public
funds to registered Co-operative Credit Banks any sums not exceeding one
hundred and fifty thousand dollars in the aggregate for the special purpose of
making loans to Rice growers (whether members or not members of the banks)
to be used by the borrowers for reaping, bagging and transporting Padi to the
place of storage appointed by the banks. The Ordinance covers on the banks a
preferent lien on such Padi, and a bank may sell the Padi, or mill it into Rice
and sell it for the recovery of loan and interest together with any expenses of
storage, milling and sale, all of w T hich may be recovered by parate execution
also. Misapplication of loans is deemed an offence.

The Co-operative Credit JBanlcs Ordinance , No. 28 of 1933.

This Ordinance has been enacted to make better provision for the constitu-
tion and management of Co-operative Credit Banks and provides for the appoint-
ment by the Governor of a Board, with the Director of Agriculture, Chairman,
for the general superintendence of all banks, and a Registrar of banks, who is
also secretary of the Board.

Part I of the Ordinance stipulates that a bank which may be registered
must be a bank established for making loans to its members for the development
o| 4 their land or for some other industrial pursuit. Provisions a/e made for the
conditions and acknowledgment of registration, appeal from refusal to register,
effect of acknowledgment of registration, incorporation of banks with limited
liability power to acquire land and dispose of property, keeping of register of
banks, and cancellation and suspension of registration by the Board,

A. SUMMARY OP AGRICULTURAL LEGISLATION IN BRITISH GUIANA. 257

Part II prescribes (a) Powers and functions of the Board ; (b) Status of
person appointed to be a member of a committee to represent the Board ; (c)
Rights and powers of the Board on taking over the management of a bank ;
(d) Return of management.

Part III deals with the operations of the banks in regard to (a) Loans to
banks from public funds ; (b) Loans by banks a preferent charge on borrowers’
property ; (c) Remedy for debts from members ; (d) Audit ; (e) Report by
Board to Government.

Part IV treats of dissolution and winding up of banks.

Part V stipulates offences and imposes penalties.

Part VI enables the Governor to make regulations for giving effect to the
Ordinance and prescribing rules for the government of the banks.

The Co-operative Credit Banlcs Regulations, 193-3.

Under these Regulations model rules are provided for the banks.

The Co-operative Credit Banks Regulations , 1937.

These have revoked Rule IX (b) of the Rules for Co-operative Credit Banks
in the Schedule to the Co-oporative Credit Banks Regulations, 1933, as amended
by the Co-operative Credit Banks Reglations, 193G, and substituted a new Rule
IX (b) therefor in regard to the disposal of a bank’s revenue.

The Co-operative Credit Banks (Amendment) Ordinance, No. 13 of 1938.

This Ordinance amends Sections 2 and 18 (2) of the Co-operative Credit
Banks Ordinance, 1933, in certain particulars to restore to the Banks the pref-
erent claim provided under the Ordinance which was affected by the provisions
of the Deeds Registry Amendment Ordinance, No. 4 of 193G.

MISCELLANEOUS.

The Public Gardens and Agricultural Shows Ordinance, No, 34 of 1935.

This Ordinance enables the Governor-in-Council to make Regulations
concerning the Government Botanic Gardens and Government? Agricultural
Stations and also with respect to the holding of Agricultural Shows.

The Government Botanic Gardens Regulations, 1936.

These Regulations, made under the Public Gardens and Agricultural Shows
Ordinance, provide for the control of persons and vehicles in the Gardens.

258

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[IX, 4.

Part II.

LEGISLATION RELATING TO INSECT PESTS AND
FUNGUS DISEASES *

The Plant Diseases and Pests (Prevention) Ordinance, No. 87 qf 1933,
(under which the similar Ordinance, No. 2G of 1920 is repealed) gives the
Governor-in-Council power to make Orders and Regulations controlling the
importation and exportation of plant material and authorising the necessary
measures to deal with outbreaks of Pests or Diseases within the Colony,
Importation of plants may also be controlled by orders made under tho Customs
Ordinance No. 7 of 1884, (Cap. 33).

(A) REGULATIONS AND ORDERS RELATING TO PESTS AND
DISEASES PRESENT IN THE COLONY.

The following aro issued under the Plant Diseases and Pests (Prevention)
Ordinance:-—

Plant Diseases and Pests (Notification) llegulalions, 1930.

The Governor-in-Council may by order published in the “ Official Gazette ”
declare any disease or post to be a notifiable disease or pest, whereupon, in
accordance with the Ordinance, the owner or occupier or person having charge
or management of land on which such a disease or pest occurs must notify tho
Director of Agriculture in writing and must subsequently carry out such steps
as the Director of Agriculture may order for the eradication or prevention of
spread of the disease or pest. The owner is liable for expenses incurred, though
payment of part or all of these may be dispensed with at the Director’s discre-
tion. The decision of the Director as to the presence or identification of a
notifiable disease or pest is final.

Order in Council No. 550 dated April 2, 1936, published in the “ Official

Gazette ” of April 11, 1930.

By this Order Coconut Caterpillar (Brassolis sophorae L.) was declared a
notifiable Pest throughout the Colony and Witch Broom ( Marasmius
perniciosus Stahel) was declared a notifiable disease in the North West District
of the Colony.

(B) ORDERS AND NOTICES RELATING TO IMPORTATION AND
EXPORTION OF PLANTS, FRUITS, SEED, ETC.

Order in Council No. 551 dated April 2, 1986, published in the “ Official

Gazette ” of April 11, 1986.

Ifjhis Order prohibits the importation into the Colony of Sugar Canes and any
planter parts thereof, of plants of grasses of any kind, and of earth or soil or
an y packages or coverings which contain o r have con tainedearth or soil. It also

•A summary of Plant Importation and Exportation Legislation in British Guiana and
the Caribbean Colonies was published in Agricultural Journal of B.G. IX, 1, p. 25, 1938,

A SUMMARY CF AGRICULTURAL LEGISLATION IN BRITISH GUIANA. 259

prohibits the importation of banana and plantain suckers without the written
authorization of the Director of Agriculture. The provisions of this Order do
not, however, apply to importations made by the Director of Agriculture for
scientific purposes.

Order in Council No. 552 dated April 2, 1036 and published in the “ Official

Gazette ” of April 11, 1936.

This Order provides that all living plants, seeds, cuttings, bulbs or other
plant parts intended for propagation, which may be imported into the Colony,
shall be examined by an authorized inspector, who> if he passes the same for
importation, shall issue to the Customs Officer a certificate on the recognised
form, permitting entry.

Under this Order also, where a certificate of examination is required by tbe
consignee of living plants or plant products exported from the Colony, the same
Shall be provided on the recognised form by an authorised inspector.

Mediterranean Fruit Fly ( Ceralitis capitala).

Order in Council No. 767 dated May 19, 1930 and published in the “ Official
Gazette ” oj May 31, 1930, amended by Order in Council No. 235 dated August
20, 1934 and published in the ‘‘ Official Gazette ” of August 25, 1934.

These Orders, made under the Castoms Ordinance of 1884 (Cap. 33) and
Amendment Ordinance, 1911, with the object of preventing the introduction of
the Mediterranean Fruit Fly ( Ceratitis capitata) prohibit tbe importation of
fruits (excepting plantains, nuts and preserved fruits) and vegetables (excepting
onions, potatoes and preserved vegetables) from all countries except the British
Isles, Canada, and the British West Indies, not including Bermuda and the
Bahamas, bnt allow the importation of Pineapples, Yams, Sweet Potatoes,
Tannias, Eddoes and DasheenB from Dutch Guiana.

Citrus.

Order in Council No. 862 dated June 8, 1937, and published in the “ Official
Gazelle ” of June 19, 1937 and Order in Council No. 868 dated June 2, 1938
andpublishcd in the " Official Gazette " of June 11, 1938.

The first of these orders prohibits the importation into the Colony of Citrus
material, including fruit, from the United States of America on account of the
danger of introducing Citrus Canker ( Phytomonas citri ) and the second prohibits
the importation of Grapefruit from Trinidad and all citrus fruits from the
remainder of the British West Indies owing to the presence of Citrus Scab
(Elsinoe'Fawcetti) on Grapefruit in Trinidad, and of Citrus Weevil ( Diaprepes
spp.) in other of the British West Indies.

Coffee

Order in Council No. 646 dated November 9, 1937 and published in the “ Official

Gazette ” of November 13, 1937,

This Order prohibits the importation of raw coffee from all countries on the
continent of tenth America and from all other countries unless the Director of

360 AOHICtTLTOftAL JOtTSKAt OF iHUtlKH «t»ASA» flX, 4.

Agriculture is satisfied that it is from a oountry in whioh the Coffee Berry-Borer
(Stephanoderes hampet) is unknown.

PlMEWTO

Notice No. 852 , published in the “ Official Gazette” of December 5, 1988.

Owing to the occurrence of Rust Disease of Pimento and of the Bay Tree
(Punenta acris ) in Jamaica, the exportation of the Pimento Plant or any part
thereof, except the dried berries used for commerce, is prohibited in Jamaica,
and their importation therefrom into this Colony is prohibited in accordance.

Rick Seed (padi).

Qj'dei in Count if No. 422 dated Aw/nsf 17, 1988 and published in the
“ Official Gazette” of St pi an bn 21, 193S.

This older prohibits the importation of Rice Heed (l'adi) without the
written authorisation of the Director of Agriculture

* P \RT III.

LEGISLATION RELATING TO LIVESTOCK, BEES AND

WILD BIRDS.

LIVESTOCK— GENERAL.

Pounds Oidmanct No. 1 of 1868, (Cap 93)

This Ordinance deals with the impounding of stray cattle and the regula-
tions controlling it.

Pound Fhh Puli s and Deputations, 1987.

These Rules reduce by 50 per cent, the pound fees payable m respect of wild
animals straying on private premises or land, but do not affect the impounding
of stress on publio premises or land.

Cattle Shalinp Previntnm Oidmana, No. 3 of 1877, ( Cap 94).

This Ordinance deals with the branding oi Cattle and the regulations which
control it, also with the movement of Cattle on the highways and the control
thereof. It also enacts that the skin of any slaughtered Cattle shall be kept for
a stipulated period for examination if required.

Cattle Tiad (Tolls) Oidtiianoc, No. 16 of 1929.

By this Ordinance the Governor-in-Council may make regulations prescrib-
ing the payment of .tolls for the passage of Cattle over the Cattlt Trail.

A SUMMARY OF AGRICULTURAL LEGISLATION IS BRITISH GUIANA. 261

Free Importation op Cattle Foods.

Department of Agriculture Notice No. 57 published in the “ Official Gazette ” of

July 10, 1937.

This notice states that under the Customs Duties, 1935, as amended by
Section 4 of the Customs Duties (Amendment) Ordinance, No. 26 of 1936, the
following cattle foods may be imported free of duty provided that their quality
is approved by the Director of Agriculture, to wit : Soya Meal extracted,
Linseed Cake, Dried Separated Milk, Meat and Bone Meal, Meat Meal,
Fish Meal (white), well known proprietary Calf Meals, Barbados Cotton Seed
Meal.

VETERINARY,

The Animals Diseases Ordinance, No, 29 of 1936.

This Ordinance provides for the proper registration of all Veterinary
Surgeons. It also states the conditions under which animals may be imported
No animal may be imported without permission of an officer appointed by the
Director of Agriculture, and any animal so imported, or suffering from disease
on arrival, may be destroyed. When disease is suspected in any area of the
Colony, the Govornor-in-Council may declare such an area to be an infected
area and stipulations are made concerning the movements of stock or carcases
into, out of or within such areas. Notification of disease must be given immedi-
ately to the Police. Diseased animals may be slaughtered, for which the
Governor-in Council may award compensation. Special provisions are made as
to outbreaks of Anthrax, calling for the inoculation and marking of animals in
tho aiea concerned. If Glanders or Farcy recur within two years in the same
building, isolation of such building may be required by the Director of
Agriculture, and by order ot the Governor-in-Council the Colonial Teasurer may
recover the cost of isolation or disinfection from the owner of the premises
concerned. It is tho duty of every Police Constable to enforce the Otdinance.
Details are given as to what constitute offences under the Ordinance and the
purposes for which the Governor-in-Council may make regulations.

Under this Ordinance The Animals (Breed and Contagious Diseases)
Ordinances, No. 5 ot 1920, (Cap. 272) and No. 38 of 1932 are repealed.

Exportation op Animals.

The Animals Diseases Regulations, 1937.

These regulations require that no animal shall be exported before it is
inspected by the Government Veterinary Surgeon, or a Veterinary Surgeon
appointed by the Director of Agriculture and is certified to be free from disease
and fit and suitably for export. A scale of fees for inspection is laid down.

AGRICULTURAL JOURNAL Of faftlTISU GUiANA. [iX, 4.

Importation op Animals.

Order in Council No. 572 dated March 19, 1957 and published
in the "Official Gazette” of April 24, 1937.

This Order states the conditions nnder which importation can be made into
the Colony of animals, carcases, fodder or litter from any of the following
specified places, to wit: Great Britain, Ireland, Canada, the West Indian
Islands, the United States, Brazil, the Argentine, French Guiana, Surinam
and Venezuela. All animals and carcases from these places are to be accom-
panied by a certificate signed by a Veterinary Surgeon on behalf of the
Government Department of the country of origin certifying that they
are free from disease, and in the case of cattle, that they have passed the
tuberculin test. Fodder or litter must be accompanied by a certificate signed
by a Veterinary Surgeon of the country of origin certifying that it is from a
district free from disease. On arrival in the Colony animals must be certified
as free from disease.

BEES.

The Importation of flees Ordinance, No. 33 of 1935.

This Ordinance permits the Governor-in-Council to make regulations for
the purpose of regulating the importation of bees and beekeepers* stock.

The Importation of Bees Begu/ations, 1930.

These Regulations prohibit the importation into the Colony of (a) honey,
combs ; (b) hives and other beekeepers’ stock which have been previously in
use ; (c) queen bees ; (d) worker bees and drone bees in any stage of develop-
ment exoept with the written permission of the Director of Agriculture.
Stipulations are made in regard to the manner and quantity in which bees and
queen bees may be imported.

The Importation of Bees ( Amendment ) Ordinance, No. IS of 1986.

By this Ordinance power is given the Director of Agriculture to destroy or
cause to be destroyed any bees or bee equipment imported in contravention of
regulations passed by the Governor-in-Council.

PROTECTION OF WILD BIRDS.

The Wild Birds Protection Ordinance, No. 31 of 1919, {Cap. 273) Amended

by Ordinance No. 27 of 1934 and by Order in Council No. 701
dated November 5, 1934 and published in the “ Official Gazette ”
of November 10, 1934.

This Ordinance schedules a large number of wild birds for absolute pro-
tection, and a smaller number for protection during the close season, from April
1, to August 1, excepting Ibises (Cari-Curi, etc.) for which the close season is
January 1, to August 1. It is an offence to kill or injure, or capture or offer for
sne any of the birds scheduled. An exception is made in the case of birds
killed of necessity in the bosh for food, and of Pigeons in the neighbourhood of
Rice fields, and Aboriginal Indians are not liable to conviction under the
Ordinance* t

REVIEWS.

Cacao and Witch Broom Disease (Marasmus peraiciosus ) of South
America.— With Notes on other species ofTheobroma. Report by Dr- F. J.
Pound , Agronomist , Dept. o/Agric „ Trinidad, on a visit to Ecuador, the Amazon
Valley and Colombia, April 1937 — April 1938. Pub, Turtle's Printerie, 06
Marine Square, Port qf Spain, Trinidad. ( 58 pp.)

The first part of Dr. Pound’s most interesting report deals with the varieties
of cacao used for oommercial purposes and the search for types resistant to Witch
Broom, In a short account of the history of Witch Broom Disease, he points
out tho havoc played by tho disease and the difficulty of economic control with
the falling price of oacao, the only practical methods of combating the damage
being to improve yields and to discover resistant or immune varieties to replace
those at present cultivated. In order to discover such varieties, it was realised
that a thorough search must be made in the cacao growing countries of South
America and Dr. Pound’s journey was the culmination of a good deal of prelim*
inary work done with this end in view.

The search for resistant varieties was finally carried to the Amazon Yalley,
when it was realised that Ecuador and the Guianas were only outlying areas of
this larger and more severely infected region. The types of cacao found in the
varying tributaries of the Amazon Valley are described in some detail.

In tho lower Amazon, trees were found which were apparently immune if
isolated and exposed to bright sunlight, while in the Upper Amazon others were
found which were highly resistant and probably immune even under such
conditions as might be found on cacao plantations.

The seoond part of the report concerns the non-commercial species of cacao
which occur throughout the region traversed and concerning whiqh there is
considerable confusion. Though all the species cannot yet be distinguished with
certainty, a number of groups of similar types havo been defined, into which
most of the known species can bo placed, though a few still remain which do not
oonform to these. The difficulties of correct determination are largely due to
lack of adequate material on which to base propor descriptions, and a multiplicity
of local names has also added to the confusion.

The third part of the report deals with the' method employed to make
available for use in Trinidad the Witch Broom resistant varieties that were found.
In order to avoid risk of introducing diseased material into Trinidad, seed was
sent to Barbados and it is being grown there in quarantine, whence it will be
possible to obtain budwood for propagation in Trinidad. The method employed
to send the original seed to Barbados is of interest, To prevent fermentation

864

AGRICULTURAL JOURNAL 07 BRITISH GUIANA.

[IX. 4.

taking place en route, the mucilage was got rid of by kneading the seed in very
dry sand, the mucilage-soaked sand then being removed by hand, after which
the seeds were packed in fresh powdered wood charcoal, slightly moist.

E. B. M.

The Principles of Cane Sugar Manufacture By J. 6. Davies. Pub.
Norman Rodger , London. 10\-. ( 140 pp„ 24 plates, 17 figures).

This book will be very useful to those who are interested in sugar manu-
facture “ amongst other things. ” Whilst we agree that the cobbler should
stick to his last, we sometimes wish that we could drop in on him and talk
cobbling knowingly though superficially. But we cannot forget our first visit
to a sugar factory, when an overstrained voice shouted unintelligible explanations
in competition with the death -cries of a phalanx of noble canes.

The book was obviously written for sugar estate overseers who wish to
know what happens after their canes disappear up the cane-carrier, but it will
also appeal to many who have to scrutinize factory reports without a very clear
idea of what it all means. Some sugar technologists may sneer at it — comparing
it with Noel Deerr, Pi insen Geerligs, Browne and Tromp — but it may make them
more readily understood when they “talk shop”, and they will be able to avoid
theawkward task of explaining pH by referring their more inquisitive friends to
page 31.

To give an outline of sugar manufacture in 140 pages is an achievement,
and the numerous plates and diagrams permit a nodding acquaintanceship
which may be developed at leisure into a better understanding.

D. W D.

NEWS.

The Department takes this opportunity of congratulating Capt. F. Barnett.
MX*., M.A., on his promotion as Commissioner for Land Settlement in Jamaica,
Capt. Barnett was appointed Depnty Director of Agriculture in British Guiana
in 1929. The district agricultural work was under his immediate supervision
and he rendered valuable assistance in connection with the working of the pure
line padi improvement scheme. He also gave a great deal of his time to co-opera-
tive schemes in relation to rice marketing and to land settlement problems.
He acted on several occasions as Director of Agriculture and as a member of the
Legislative Council. He takes with him the good wishes of his colleagues for
success in his new appointment.

Consequent on the promotion of Mr. J. D. Gillespie, B.Kc., to be Agricultural
Officer, Sierra Leone, the Secretary of State for the Colonies has been pleased to
appoint Mr. T. Bell, n.s.A. (Hons.), (Toronto), A.l.o.T.A., to be Agricultural
Superintendent in British Guiana. Mr. Bell was the Assistant Manager of the
Government Stock Farm and Agricultural Station in Palestine andartivedin
the Colony oo December l:i.

Consequent on the promotion of Mr. H. A. Cole to the Senior Grade, His
Excellency the Governor has been pleased to appoint Mr. 0. F. J. Churaman,
Dip. Agr., to be an Agricultural Instructor as from August 24, 193t>.

Mr. L. D. Cleare, F.lt. Eat. a., Entomologist, returned from leave of absence
on October 21. While on leave Mr. Cleare attended the seventh International
Entomological Congress held in Berlin from August 14 to 21.

The Department offers its congratulations to Mr, H. D. Huggins, M.sc., Dip.
Agr., Agricultural Superintendent, on the occasion of his marriage on Novem-
ber 1.

Mr. W. G. Delph, Registrar of Banks, left the Colony on six months’
leave of absence on December 5. Inconsequence, Mr, A. A. Thorne, Account-
ant, has been appointed to act as Registrar of Banks and Mr. C. A. LaBhley of the
Treasury Department a3 Accountant.

Mr. H. Parker, General Manager of Government Rice Mills iivthe Federated
Malay States, who was detailed to investigate the possibility of erecting
Central Rioe Mills in British Guiana, particularly in Essequibo, and generally to

266 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [IX, 4,

consider rice milling problems in the Colony, left on Ootober 23, his visit having
lasted rather over a month. Daring his stay in the Colony, Mr. Parker made
several visits to rice-growing districts, where he inspected the rice mills and dis-
cussed the problems with persons engaged in the industry. He met the
Esseqnibo Coast Committee on several oeoasions. It is hoped that his report will
enable a step forward to be made in the milling end of the industry.

Among the visitors to the Department have been Major G. St. J. Orde
Browne, O.B.E., Labour Adviser to the Colonial Office and his Secretary, Mr. R.
Norris.

The first quarterly meeting of the B.G. Poultry Association was held at the
Department of Agriculture on October 24, a large number of members being
present. The President gave an interesting address on the “ Production and Care
of Eggs ” which was much appreciated.

LEGISLATION

Legislation has recently been enacted prohibiting the importation of nee
seed (padi) under Section 3 of the Plant Diseases and Pests (Prevention) Ordin-
ance, 1935.

An Order in Council under Subsection (3) of Section 4 of the Sugar Quota
Ordinance, 1937, has recently been passed allocating the quota for the year 1st
September, 1938 to 31st August. 1939. The allocations are as follows :

Factory

Manufacturer

Allocation
in tons.

Albion

The Corentyne Sugar Company Limited

13,195

Blairmont

S. Davson & Company, Limited

15,184

Cane Grove

Bookers’ Demerara Sugar Estates, Limited

4,221

Diamond

The Demerara Company, Lmited

23,600

Enmore

The Enmore Estates, Limited

10,771

Friends A. Mara

The New Friends, Limited

500

Houston

Plantation Houston Sugar Estates Company,
Limited

1,799

La Bonne Intention

The Ressouvenir Estates, Limited

9,914

Leonora

The Demerara Company, Limited

10,400

Lusignan

The Enmore Estates, Limited

10,398

Ogle

The Ogle Company, Limited

4,408

Port Mourant

Port Mourant, Limited

13.630

Rosehall

Bookers’ Demerara Sugar Estates, Limited

14,698

Ruimvelt

The Demerara Company, Limited

1,600

Skeldori

Bookers’ Demerara Sugar Estates, Limited

10,643

Uitvlugt

Bookers’ Demerara Sugar Estates, Limited

11,937

Versailles &

Schoon Ord.

Plantation Versailles and Schoon Ord,

Estates, Limited

4,408

Wales

West Bank Estates, Limited

5,374

PLANT AND SEED IMPORTATION.

Introductions by the Department of Agriculture for the period
September — November, 1938.

Name

Quantity. 1

Whence Supplied

Economic .

Vegetable Seed, 13 varieties

lb.

Sutton & Sons (Calcutta).

Vegetable Seed, Assorted 1

lb., 14 oz.

Sutton & Sons, Reading,
England,

Onion Seed, 2 virieties

lb.

Hamilton & Co., Teneriffe.

A^cado Pears, Guat email variety 1

seeds

Director of Agriculture.
Mauiituis,

Rexoro Padi

lb.

Dr. G. Stahel, Agr). Expt. Stn ,
Paramaribo.

Lettuce, 4 varieties 1

oz each

Ferry ‘Morse Seed, Co.,
California.

(

Ornamental.

Hyphaene conacea , M.ut 1

seeds

Royal Bot. Gardens, Kew.

„ parvula

seeds

do.

Piggftetia elata

; 44

seedlings

Coconut Grove, Palmetum,
Florida

Coopei ia pechnmihita

bulbs

American Amaryllis Society,
Flonda.

Crmum ameriramim

bulbs

Ldium cat < shun

bulbs

do.

Zephymnlhe atama^ro

bull>s

,, pulch'tla

bulbs

„ t) (attar

1 1

bulb

Hibiscus, 18 varieties

i 12G

cuttings

Impen.il College of Tropical
Agriculture, Trinidad.

PUcairvia rectn rata

1 packet j

Da\id Barry & Co., California.

„ Alternttmu Lem.

do.

Guzmania species

do.

Flower Seeds, Assorted

lb., 3 oz.

Hurst <£ Sons, London.

1 & 9

pkts.

METEOROLOGICAL DATA-JULY TO SEPTEMBER, 1938.

fieoording Stations &
Months.

Rain-

fall.

NUMBER OF DAYS OF RAIN

Botanic Gardens.

Total

Inches.

10 to
| 50 Ineh

•50 to

1.00 Inch

5 5

« fi s>!

* 8 «S

e» ) w

Total days

July

1274

August

14 96

September

1-85

...

Totals

Means

...

Berbice Gardens.

July

933

August

12.63

...

September

.57

...

Totals

22 53

Means

...

Onderneeming.

July

10.41

1 •••

I 11

1 5

...

August

i ^

... IS

j .

September ... 5-59

! ^

1 1

| I ]

Totals

20-17

1 8

Evapo-

ration

Inches

Air Temperature
and Humidity.

85-1 74-9 80-0 88-6

1 86-3

75-0

80-6 83-.J

5-00 , 8S-2‘ 75^i 82. 5 80-1

1 13-58

Means

I 86 .) 75.6 81-0 824

88-0 74.9 81.4 78.6
89.7 74-9' 82 3 80-7
i 91*1 76.6 83.8175.7

89.6 75-5 82 5> 78-3

I !

85.0, 72.4
87-2, 73.5

88-4|

74. 5j

78.7 92.8

80-1,92.6
81. lj 90.9

86-9 73-5 80.1:

Hosororo,

North West District I
July ...J

8-04

u !

! _ I

August ...j

17-20

4 !

8 :

...

September ...j

4-57

9 | 11

)

...

... i

...

Totals •

29-81

24 30

i 1

...

Means

...

... | ...

{

|...

...

86. 5| 69-9

78-2!

92-1

87-8

70.*5| 88.4' 79-4 89-0
70-6| 89-6{ 80.1 87.5

j 75-9

82-6

79.2 88-1

CURRENT PRICES OP COLONIAL PRODUCE

From The Commercial Review, Journal of the Georgetown Chamber
of Commerce, Vol. XXI, No. 11, Wednesday, 30th November, 1938 .

SUGAR.

Per 100 lb. net 3 lb. per Bag allowed for tare

Dark Crystals for Local Consumption... 13.30

Yellow Crystals do. do $4.00

White Crystals $4.75

Molasses Sngar none offering.

Above Prices include Excise Tax of 90c.

RUM.

Imperial Gallon. Cask included.

Coloured, in Puncheons — 40 to 42 O.P...(for export). ..60c.; Hhds. 52c., Barrels 77c*

White, in Hogsheads — 40 to 4.) O.P...(for local consumption) 45 to 55c.

MOLASSES.

Per Imperial Gallon. Naked.

Yellow (firsts) 10c.

Yellow (seconds) 5$c.

RICE.

Rice per Bag of 180 lb. gross. Brown Super $3.60 — $3.75 ; Extra No. 1,

$3.00 — $3.25 ; White, None available. Lower Grades $2.25 — $2.50 as to quality,
Padi..,., ....per Bag of 143 lb. gross, $1.20 — $1,50 as to quality.

GENERAL.

Gold, Raw average per oz. $27 to $28.

Diamonds, — pro rata as to quality average per carat $10 to $11.

Timber, Greenheart, (Lower grade measurements)... 40c. to 60c. per c. ft. ;

for export 72c. to $1.00 per c. ft.

do. Railroad Sleepers — (Mora) $1 .68 each.

Greenheart Lumber $70 to $80 per 1,000 feet.

Crabwood Lumber $60 to $75 per 1,000 feet.

Shingles, Wallaba, 4 x 20 and 5 x 22 inches, $4.50 to $6.00 per M.

Charcoal, Capped for shipment 72c. to 85c. per bag.

Firewood $2.50 per ton.

Coconnts...Selects, $9.00, culls $6.00 per M... Copra $2.00 per 100 lbs. prime Copra.

Balata... Venezuelan, none. Local Sheet.. .36c. to 38c. per lb.

Cocoa.I.. 19c. to 19ic. „ „

Coffee 8c. to 9c. „ „

N.B.— Duty Payable on value at tune of Importation and rate of exchange on day of
arrival.

INDEX TO YOL. 1A.

1938

Page

Agriculture — Fifteenth Meeting of Advisory Board of ... ... 178—182

Agricultural Legislation in British Gniana and the

Caribbean Colonies ... ... ... ... 25 — 38

Agricnltnral Legislation in British Gniana — Summary of ... 24 (i — 262

Amazon Fly in British Gniana, 1937— Status of the ... ... 12 — 24

Appointment of Bell. T. as Agricultural Superintendent ... 265

„ Churaman, 0. F. .T. as Agricultural Instructor ... 265

„ ,. Fraser, H. A. to act as Government Veterinary

Surgeon ... ... ... ... 127

,. „ Williams, C. H. B. as Sugar Agronomist

and Plant Breeder ... ... ... ... 67

Bees — Summary of Legislation in British Guiana ... ... 262

Beekeepers* Association— Minutes of the Fifteenth Meeting

of the British Gniana ... ... ••• 64 — 66

Beetles — Damage caused to Bum Puncheons by Boring ... 237 — 245

Bell, T.— Appointment of, as Agricultural Superintendent ... 265

Board of Agriculture — Fifteenth Meeting of the Advisory ... 178 — 182

Bone, T.— Retirement of, as Government Veterinary Surgeon ... 127

Boron in Agriculture ... ... ••• ••• ^7 — 119

Botanic Garden — The Georgetown : Some Notes on

its Early History ... ••• ••• ••• 207— 216

Bourne, C. L. C. — “A Milling Test on Sixty Padi Varieties” ... 163—168

British West Indies Fruit and Vegetable Council ... ... 190 — 125

Bronze-Leaf Wilt Disease of the Coconut Palm ... ... 54 — 57

Burnett, F.— “Results of Padi Varietal Trials and Extension

Work. 1937” ... ... - - 82-100

„ „ —Promotion of, to be Commissioner for Land

Settlement, Jamaica ••• ... ••• 265

Cacao and Witchbroom Disease of South America ... ... 263—264

Cameron, C. — “ The Boring Points for Refractometer Tests
of Sugar Cane”

• ••

47—50

Index to Vol. IX.

Dane in British Guiana— A Water Rat Damaging

.. — The Boring Points for Refractometer Tests of ...

Case, G. 0. — “The Use of Vegetation for Coast Protection”
Child, R. — “Edible Coconut Oil”

Chitraman, 0. F. J. — Appointment of, as Agricultural Instructor
Citrus fruit — Legislation prohibiting the importation of from
the British West Indies
Clarification of Sugar Syrups ... ...

Clears, L. D — “A Water Rat Damaging Sugar Cane in
British Guiana ”

«. — “ Damage Caused to Rum Pancheons by

Boring Beetles”

» .. — “Plant Legislation in British Gniana and the

Caribbean Colonies” ... <..

.. — “Status of the Amazon Fly in British Guiana, 1937

Coconut Oil— Edible

., Palm — Bronze-Leaf Wilt Disease of the
„ Wilt in Essequibo and Pomeroon Districts
Coconuts — Summary of Legislation concerning, in British Guiana
CofFee Quality

Cole, H. A. — Promotion to the Senior Grade of
Agricultural Instructors

Credit— Summary of Legislation concerning, in British Gniana

Page

217—229

47—50

4-11

109—116

265

120

61—62

217—229

237- 245

25 — 38
12-24
109-116
54—57
147—152
254-255
51—53

Current Prices of Colonial Produce

... 256—257
72. 131, 193, 270

Dairy Heed, A Grade

Dhal — Methods of Preparing Marketable

Diatraen

Dtjthie, D. W. — “ Coconut Wilt in Essequibo and
Pomeroon Districts”

•• •> - “ A Milling Test on Sixty Padi Varieties’

153—162

169—177

12—24

147—152

163-168

Edible Coconut Oil
Editcgials :

Economic Stock-Raising
Pasture Grasses
Rice-Situation

llojal Commissions— Past and Present

109-116

133-134

1-2

73—74

195—196

Index to Vol. IX

▼

Fertiliser and Variety Position of the Sugar Industry, IV ... 101— I0K

Fraser, H. A. — “A Grade Dairy Herd” ... ... ... 153 — 102

„ „ — Appointment of, to act as Government

Veterinary Surgeon ... ... ... 127

Fruit and Vegetable Council, British West Indies ... ... 120 — 125

GAYWAfiA, P. M. — “The Cultivation of the Pigeon Pea {CnjmiUH

rtijaii) and the Methods of Preparing Marketable Dhal” ... 109 — i 77

GlWjioi,!, G — “ Malaria in British Guiana,” I, LI, III, 75-81, 135- 140, 197 — 200

OiULEsriK, J. D. — Promotion of ... ... ... 127

Grasses — Presidential Address at the 4th International

Grassland Congress ... ... ... ... 39—40

Importation of Plants, Legislation relating to the ... ... 25 — 38

Legislation— Allocation of Sugar Quota for year 1938— 39 ... 207

., —Appointment of Plant Inspectors ... ... 02

„ — Control of Sugar Experiment Stations ... ... 62

—List of Registered Veterinary Surgeons ... ... 02

,, in British Guiana and the Caribbean Colonies, Plant ... 25—38

., „ „ — Summary of Agricultural ... 240—202

„ force in the Caribbean Colonies relating to the

importation of plants — Summary of ... ... 30 — 37

„ prohibiting the importation of plants into Trinidad ... 120

„ „ „ „ „ all citrus fruit from

the B.W.I. ... ... 120

„ „ ,. „ rice seed (padi) ... 207

Livestock Importations ... ... ... ... 08

„ Industry — A short History of the llupununi Savannahs with

special reference to the ... ... 230 — 236

„ — Summary of Legislation concerning, in British Gniana 200 — 202

Lonchocarpii* sp. ... ... ... ... ... 57

Malaria in British Guiana, I, II, III ... 75—81, 135—146,197 — 2( 0

Mangrove ... ... ... ... ... ... 4 — 11

MarTYN, E.B. — “The Georgetown Botanic Garden: Some Notes

on its Early History ” ... ... ... 207— 210

Index to Vol. l£

Pag®

Meteorological Data ... ... ... ... 70 — 71,130,192,269

Milling Teat on Sixty Padi Varieties ... ... ... 163 — 168

News ... ... ... ... 67—68.126—128, 190,265—266

Notes :

Boron in Agriculture ... ... ... ... 117 — 119

British West Indies Fruit & Vegetable Council .. ... 120 — 125

Bronze-Leaf Wilt Disease of the Coconut Palm ... ... 54 — 57

Clarification of Sugar Syrups ... ... ... 61 — 62

New ornamental Plants Introduced into the Botanic

Garden during 1937 ... ... ... ... 119 — 120

Padi & Rice Production in India and Burma ... ... 183 — 189

Rotenone Yielding Plants of South America .., ... 57

Soil EroBion ... ... ... ' . . ... 39 — 61

Surinam and Curacao ... ... ... ... 58 — 59

Oil, Edible Coconut ... ... ... ... ... 109 — 116

Padi — A Milling Test on Sixty Varieties ... ... ... 163 — 168

„ and Rice Production in India and Burma ... ... 183 — 189

„ Varietal Trials and extension Work, 1937 — Results of ... 82 — 100

Parker, H.— Visit of ... ... ... ... 190

,, „ — Departure of ... ... ... ... 265

Pigeon Pea (Cajanvs mjan) — The Cultivation of ... ... 169 — 177

Plant — Legislation in British Guiana and the Caribbean Colonies ... 25 — 38

„ & Seed Importation ... ... ... 69, 129, 191, 268

Plants — Legislation prohibiting the importation of, into Trinidad ... 120

Prices of Colonial Produce ... ... ... 72,131, 193,270

Quota — Allocation for year 1938-39 of Sugar ... ... 267

Rat Damaging Sugar Cane in British Guiana — A Water ... ... 217 — 229

Ref raffometer Tests of Sugar Cane — The Boring Points for ... 47 — 50

Report :

The Fifteenth Meeting of the Advisory Board of Agriculture 178 — 182

Results of Padi Varietal Trials and Extension Work, 1937 • ... 82 — 100

index to Vol. IX

Reviews :

Cacao and Witchbroom Disease of Sonth America...
The Practical Aspects of Copra Deterioration
The Principles of Cane Sugar Manufacture
Rice — Average Prices of

„ — Summary of Legislation concerning, in British Guiana
„ and Padi Production in India and Burma
Rotenone Yielding Plants in South America
Rum Puncheons — Damage Caused to, by Boring Beetles
Rupununi Savannahs — A Short History of the, with special
reference to the Livestock Industry

263—264

264

252—254

183-189

237—245

230—236

Seed and Plant Importation ... ••• ... 69,129,191,268

Selected Articles :

Boring Points for Refractometer Tests of Sugar Cane 47 — 50

Cultivation of Cajanus cajan and Methods of Pre-

- paring Marketable Dhal ... ... .. 169 — 177

Coffee Quality ... ... ... ... 51 — 53

Edible Coconut Oil ... ... ... ... 109—116

Presidential Address at the 4th International Grass-
land Congress ... ... ... ... 39 — 47

Soil Erosion ... ... ... ... ... 59 — 61

Spartina Grass ... ... ... ... ••• 4 — 11

Sugar — Allocation of Quota for year 1938-39 ... ... ... 267

„ —Summary of Legislation concerning, in British Guiana ... 250—251
„ Cane — The Boring Points for Refractometer Tests of ... 47—50

„ „ in British Guiana — A Water Rat Damaging ... 217 — 229

„ Industry — The Variety and Fertiliser Position of the, IV ...' 101 — 108

„ Syrups, Clarification of ... ••• ••• ••• 61 — 62

Statledon, R. G.— Presidential Address at the Fourth Inter-
national Grassland Congress ... ••• 39 46

TtJRNEA, H. E— “ A Short History of the Rupununi Savannahs

with Special Reference to the Livestock Industry” r .

230-236

Use of Vegetation for Coast Protection— The

Index to Vol. lit.

viii

Varietal Trials and Extension Work in Padi, 1037 — Results of ... 82 — 100
Vegetation for Coast Protection — The Use of ... .. ... 4—11

Water Rat Damaging Sugar Cane in British Guiana . ... 217 — 229

Williams, C. H. B.— “The Variety and Fertiliser Position of

the Sugar Industry, IV ” . ... 101 — 108

., ,, - Appointment of, as Sugar Agronomist and

Plant Breeder ... ... ... 67

Wilt Disease of the Coconat Palm — Bronze-leal . . ... 34 — 57

„ in Essequibo and Pomeroon Districts— Coconut .. ... 147 — 152T

THE

Agricultural Journal

British Guiana

DEPARTMENT OF AGRICULTURE
GEORGETOWN
BRITISH GUfANA,

Vol. X, No. i.

March, 1939.

The

Agricultural Journal

British Guiana

l5goq

PUBLISHED BY

THE DEPARTMENT OF AGRICULTURE,

GEORGETOWN. BRITISH GUIANA

Price

• a
aa

6d.

DEPARTMENT OF AGRICULTURE.

Director of Agriculture
Deputy Director

ADMINISTRATION

... ... Prof. The Hon. J. Sydney Dash,

B.Sc. (Agric.)

(vacant)

L. D. Clcare, F.R, Ent. S. (acting)

Clerical Staff.

Senior Clerk
Registrar of Banks

Class III Clerks

Probationers

Librarian

RESEARCH BRANCH.

Botany and Plant Pathology

Hotauiht— Plant Pathologist and Supei intend-
cut. Botanic ( hardens :

E. B. Martyn, B.A., A.l.C.T.A.

Technical A Militant .*

N. Persaud

Chemistry

C hr mint •

D. W. Duthie, M.A . B.Sc., l’h.D . F.I.C.

Assistant Chemist :

C. L. C. Bourne

Economics

Agricultural Economist .

H. 1). Huggins, M>c., Dip. Agr.

Entomology

Entomologist .

L. l>. Clcaro. F.U. Eut. S.

Technical Assistant :

C. Williams

Rice

Assistant Plant Uriah r :

P. A. Chan Choong, B.Sc., A.l.C.T.A.

Sugar

(In co-operation with the Sugar Producers)

Sugar Agronomist and Plant Hradir:

' C. H. B. Williams, M.A., A.l.C.T.A,, Dip.
Agr.

Labomtory Assistants :

H. B. SingK

A, V, Wan-Ping, Dip. Agr.

Statistical Clerk ;

J, B. Bourne

J. F. Irving, M.C.

/ W. G. Delph (on loa^ e)
j A, A. Thorne (acting)

] C. A. Lashley (acting)

| Miss D. M. Terrill

Miss M. Chcong
P. O. Jackson
, S. A. Adams
Miss S. Lord
^ Miss R. Delph

Miss Y. Chan- Choong

LIVESTOCK BRANCH

Veter mart/ Surgeon :

Vacant

H A Fraser, B.Y Sc (acting)

FIELD BRANCH

Agricultural Superintendents :

Berbice — A. A. Abraham
Demerara, East — E. M. IVterkin
Demcrara. East Bank— H. D. Huggins,
M.Sc., Dip. Agr.

Demerara. West — E. G. Benson, B.Sc.,
A.l.C.T.A., Dip. Agr.
Esseijtiibo— T. Bell, B.S.A., A.l.C.T.A.

Assistant Agricultural Superintendent :

Berbice— E. M. Morgan
Agricultural Instructors :

Berbice— O. F. J. Churam.m, Dip. Agr.
Botanic Gardens — H. A. < ole
Demerara, East — C. C. Dowding, F.L S.
F.R.H.S.

Demerara, East Bank— I. Dewar (acting)

Agricultural Assistants:

Demerara, East — J. lndrobeharry
Esscquibo — H, B. France

Ter finical . A ssi.sfants ;

Demerara, East — W. A. Bovell

Essemiibo— A. W. Sears

North West District— L? E. McKinnon

Sugar

Fit Id Manager (Central Station)

C. Cameron

Field Assistants :

L. A. Forte
B. A. McArthur

METEOROLOGICAL BRANCH

Technical Assistant :

D. D. Blackman

Meteorological Assistant :

J. E. Isaacs

RICE GRADING BRANCH

Grading Inspector :

H. E. H. Gadd

Technical Assistants :

R. H. Ross
G. L. Leitcli

ADVISORY BOARD OF AGRICULTURE

Director of Agriculture, Chairman, ex officio.

Deputy Director of Agriculture, Vice-Chairman, ex officio.
Hon. Peer Bacchus ... ... ... \

Hon. R. E. Brassington ... ... ... I

Hon. J. W. Jackson ... ... ... j

Hon. F. J. Seaford, o. ile. ... ... ... >

Mr. S. Andries ... ... ... ... (

" R. B. Hunter ... ... ... )

„ W. H. Richards ... ... /

Members

SUGAR EXPERIMENT STATIONS COMMITTEE.

Director of Agriculture, Chairman, ex-officio.
Hon. M. B (>, Austin, o.iu:.

Mr, G. M, Kcclee
„ J. C. Gibson
t , A. Murison

„ L. Lywood (acting for Mr. R. E. Rhodes)
„ J. Bee

Georgetown
Pin. Biainnonf
Pin, Port Mour.int
Pin. Uitvlugt.

Pin. Leonora
Pin. Albion

( Representing
the Sugar
Industry
/ which main-
I tains the
' Stations

COOPERATIVE CREDIT

Director of Agriculture, Chairman, cx-nffirio.

Hon. J. \V. Jackson
Rev. A. K. Dyett ...

Mr, C. Farnum ...

„ J. L. Wills ...

BANKS’ BOARD.

\ Members

DISTRICT AGRICULTURAL COMMITTEES

EAST DEMERARA

Director of Agriculture, Chairman
District Commissioner
Deputy Director of Agriculture
Hon. J. I. dc Aguiar
Hon. E. M. Walcott
Mr. S. Andries ...

,, M. Ghani
,, W. H. Richards
n J.E. Wills ...

Members

Director of Agriculture, Chairman
District Commissioner
Deputy Director of Agriculture
Hon. J. W, Jackson
Dn the Hon. J. B, Singh
Mr. R. P. Carryl
„ J. C. DaSilva
R. B. Hunter '

„ A. Mhrison ...
m W, Ramdeholl
♦, A. Rayman ...

WEST DEMERARA

Members

CONTENTS

(Vol. X, No. 1.)

PAGE

EDITORIAL— 1

ORIGINAL ARTICLES.

Malaria in British Guiana,

Parts IV. and V. ... ... <7. <hgholt, M.Ih (If.), .1/ (hmd.),

D.T.M. ,(• II. (Eng.) ... ... 4

Results of Padi Variety ‘

Trials, 1 ( .K38

. I\ A . Cltan-Choon</>

It. Sr., A.I.C.T.A.

Results of Recent Experi-
ments with Sugar Cane

. C. II . />’.

Dip.,

Williams*
Aijr .

M.A., A.I.C.T.A.,

Catalogue oJ the Lr/n<iupf< ra
rJtup t I wont (Butterllies)

of British Cuiami

. 1 . nun.

FJI. Knf .

S. ...

NEWS

...

PLANT AND SEED IMPORTATION

...

METEOROLOGICAL DATA

i:»

ILLUSTRATIONS

Ftrixc Pvge

Plate

L — Pig-

1 — Distribution of Malaria along the Guiana
coast between the estuaries of the Esse-
quiboand Corentyne Rivers. The average
rainfall at various points along the coabt
is also shown ... ... ... f>

Plati.

, TI. -Fig.

2 — The trend of the rainfall and malaria
incidence curves as registered at Mac-
kenzie on the Demerara River, in 192t> ... 7

Plate

III.— Fig.

3 — The average (1908 — 1930) and the 1937 — ^

1938 rainfall, along with the number of

cases of malaria recorded up to June 1938 ... 8

Plate

IV.— Fig.

•

1 — Rainfall and malaria on Bath Estate.

1937—1938 ... ... ... 9

Contents— Continued.

Facing Pagb

Plate V. — Diagram V. — Trend of the crude Vital Index

on a group of live estates aggregating
a population of 20,1167 which are free
from endemic malaria ... 10

Plate VI.— Diagram VI.— Crude Vital Index curve, 11*20 —

1037 from a group of 10 Sugar Estates,
aggregating a population of 20,832, which
are subject to endemic malaria (spleen rate
from f> to 30%) ... ... ... 11

Plate VII.— Diagram VII. — Crude Vital Index curve, 1020 —

1030, from a group of 7 Sugar Estates,
aggregating a population, of 13,876, which
are subject to severe endemic malaria
(spleen rate 30 to 60%) ... ... 12

Pl\TE VIII.— Pig. 1 - Xuptvgt'nes hymn (lorim. Female ... 26

„ „ —Fig. 2 — Crrahrun mutilln <vnne,nt subsp. nov.

Female (Type) ... ... ... 26

„ „ —Fig. 3 — Psendosrnda wuua Hull. Male (Type) ... 26

,, ,, — Fig. 1 — lMnumus heoalr ctcnret Hall. Male ... 26

„ — Fig. •) — Vatayrammn Idas MtilL Female Underside ... 26

„ — Fig. 6 — Pyrrhoijyru stmlonnus Fruhst. Female ... 26

M „ —Fig. 7— Anna pithyma morena Hall. Female ... 26

„ „ — Fig. 8 — Anlirrfuru tayyeUnn rodwayi subsp. nov.

Female (Type). ... ... ... 26

„ „ — Fig, 0 — Dtsniorpkia rrisiu rontunw subsp. nov.

(Type) ... ... ... ... 26

(All figures slightly reduced).

Guiana.

The

Agricultural Journal of British

March, 1939.

EDITORIAL.

RICE DEVELOPMENT.

It is seldom easy to persuade a large number of individuals to follow a
common course ; it is seldom easy even to get them to agree that a common
course is worth following. It is no easier when many of those concerned are
farmers who, as a class, have never easily sunk their individualities : win n, in
addition, there are conflicting interests, the task is definitely hard. A case in
point is the local rice industry which lias found it difficult to organise itself
into effective business unics for purposes such as milling or marketing.
Organisation for these ends has been elusive whether attempted by anybody
within or without the industry.

In the economy of the Colony, rice is second in impoitance to sugar.
In most areas, rice, where now grown, has followed second on empoldered areas
where sugar was first established. In all areas where both crops are
grown, rice is second in importance in providing employment and meeting the
charges for essential sen ices ; sugar is first. Xor are these the limits of this
association. In those areas where the two crops exist together, the problems
of rice cause only that amount of concern in the vicinities affected which the
troubles of a secondary industry may be expected to arouse. This is the ca6e,
generally speaking, in East Demerara, West Demerara and on the Corentyne ;
on the other hand, where rice exists without sugar, the situation is different —
especially in a district such as Essequiho which formerly knew the production
of both crops and where sugar, once the mainstay, for one reason or another,
goes out of cultivation. Rice is called on there to bear the responsibility in
full which formerly it did in part in maintaining the standard of living of the
community ; in such circumstance, the public hears a good deal of the troubles
of rice.

In 1910 there were on the Essequiho ('oust 0,471 acres under cane ; in
1920 tips had fallen to 5,130 acres, in 1931 to 890 acies and in 1930 the last
sugar estate, Hampton Court, ceased grinding. In the meanwhile, sugar had
disappeared not only from the Coast, but from the whole Essequiho area, for the
only other grinding factory — Pin. Marionville on the island of Wakena&m — had
gone out of operation in 1930. It was clear that the new situation was having
a far-reaching effect on those persons living and having financial interests in
Essequiho, and Government appointed a Commission in 1934 to make recommen-
dation as to what should best be done. As rice prices had fallen to uneconomic

2 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 1.

levels, the project to which the Commission gave most thought was the keeping
alive of the sugar industry in the area but, for financial reasons, Government
found it impossible to take this course.

The position in the meanwhile grew worse ; sugar production was restricted
and it became difficult for labour from Esseqnibo to obtain enough seasonal
employment on sugar estates in other districts of the Colony.

With the pressing necessity for rice to give the highest possible returns to
the cultivator, it seemed desirable that the industry’s major problem, milling,
be tackled. Thus, last year, a committee was appointed to go into the “feasibil-
ity of establishing at Anna Regina or some other central position a central rice
mill.” Shortly after tin* committee began investigations, the Secretary of State
for the (/(/lonies arranged for Mr. H. Parker, General Manager of the Government
Rice Mill, Perak, Federated Malay States, to visit British Guiana to advise on
the problems associated with changing over from small scale to large scale
milling and to make recommendations with regard to the industry generally.
Mr. Parker’s report has recently been published as lihs been the committee’s
report as Sessional Papers Nos. 3 and 4 of 1939 respectively.

Mr. Parker leaves no doubt as to w hat his findings are. He expresses
himself emphatically. The pad i grown in British Guiana, he considers “of
excellent quality-far superior to that of Malaya,” but of milling the view is
different . “The major complaint of the psidi cultivator is that he cannot make
sufficient profit by its cnlti\ation. Unfortunately all the inefficiencies in
handling, milling and marketing tend to reduce that profit. The only solution
is for the Government to erect a central mill”. Some of the advantages which
he points out will result from central milling are : —

(1) Reduction of overhead charges ;

(2) Reduction in fuel costs as construction of boilers will permit
burning of padi-husk ;

(3) Uniformity in milling :

(4) Recovery of by-products :

(3) Storage oi parboiled padi resulting in controlled output of rice ;
forward contracts could then be made ;

(t!) Reduction in costs of articles such as bags, etc, which could be
bought in wholesale quantities.

(7) Low marketing costs effected bj single selling.

•

The Essoquiho Coast liico Committee's report, like Mr. Parker’s, strongly
advises the erection of a central mill in Essequibo, the Committee’s report dis-
easing in more detail the domestic problems that will arise. Some of the chief
recommendations in the Committee’s report are : —

£1) That Government provide fands in the form of a free grant for the
erection and working capital of a central mill.

fcfcltORtAL. 3

(2) That, in the area covered by the central mill, the operation of
other mills be prohibited.

(3) That compensation be granted to proprietors of mills which are
put out of operation.

(4) That the price of padi be fixed by the central mill at the com-
mencement of each crop,

(5) That the mill make crop advances to land-owners on the basis of
contracts for the supply of padi.

(6) That the central mill itself dispose of its rice for export and for
domestic consumption.

(7) That Government grant loans to certain land-owner millers in
Essequibo to enable them to pay off their indebtedness to merchant
creditors in Georgetown.

The Committee makes it clear that after experience has been gained in
Essequibo with a central mill, others will and should follow in the several rice
producing areas. With the advent of central milling and the more efficient
control of the business end of the industry, the future of the Colony’s rice
industry is thought to be more promising than at any time previously. It would
appear that the Essequibo Coast Rice Committee and Mr. Parker have reasoned
together with credit to themselves and advantage to an industry which though
second in importance to the Colony as a whole is of first and vital importance to
Essequibo.

BERBICE AGRICULTURAL EXHIBITION. *

Arrangements are now well in hand for the County Agricultural Exhibition
which is to held in tho Colony House grounds, New Amsterdam, Berbice on
Friday, April 11. The success of the effort must depend to a very large extent
on the actiye help given by the agricultural community, but the Exhibition, being
a County Show, must largely lely for its support on Berbice.

Efforts have been made to ensure that farmers in all areas are acquainted
with the date, tho object of the Exhibition and the methods of preparing products
for exhibition. No entrance fee will be charged for exhibits and transport
facilities are being arranged which, it is hoped, will enable exhibitors to transport
their products with the minimum of trouble and expense.

ORIGINAL ARTICLES

MALARIA IN BRITISH GUIANA.

G. GIGLIOLI, m.d. (It.) M.B c.P. (Loud.), D.T.M & H. (Eng.)

Medical Adviser to the Sugar Estates of British Guiana.

Pakt IV. THE DISTRIBUTION OF MALARIA ON THE COASTLANDS.
GENESIS OF MALARIAL EPIDEMICS.

In the previous sections, the life history of A . darling! , the local malarial
vector, has been studied and the existence of certain factors ascertained, which
tend to limit the distribution of this species and its seasonal incidence. Some
of these factors, as water and soil salinity and acidity, influence this mosquito in
its developmental stages, and thus limit the extent of its breeding areas ; others,
such as atmospheric humidity and air movement, act directly on the adult
insect and tend to influence its range of flight and its survival.

We have attributed the uneven distribution of malaria throughout the
Colony to variations in these factors. High soil and water salinity or acidity,
atmospheric dryness and active air movement are all factors which are inimical
to A . darling L Conversely, soils and surface waters of low salinity and only
slightly acid, or neutral in reaction, offer suitable breeding sites ; a humid and
quiet atmosphere will allow the adults of this species to fly over a much wider
range and will favour their survival for a longer period.

On the West Coast of Demerara the land is sufficiently high to allow
natural drainage by gravity. The salt soil belt is very narrow and the cane
cultivation and rice beds, with their net of irrigation canals, extend right up
to the public road ; high coarida {Awcennia nitida) and other bush, and the
thick groves of coconut palms, mangoes and other fruit trees which mark the
nearly continuous ribbon-like village which extends for many miles along the
public road, form efficient wind barriers. A. darling i finds suitable breeding
and living conditions right up to the sea wall and malaria is more or less highly
endemic throughout this whole coastal section.

On the East Coast of Demerara the land is low T er, and natural drainage by
gravity is not possible ; surplus surface waters must be disposed of by pumping.
The front land soils are salt and their surface waters brackish. For this reason
th^ge lands are mostly uncultivated and used only for pasturage*

At Ogle the salt front lands extend for approximately 1 mile south of the
sea wall ; this belt tends to become broader proceeding eastwards along the
Coast

Malabia I» BBltflSfi gttiaXa. S

The malaria rate, which is high on the estates situated nearer Georgetown,
tends to fall progressively as the salt belt gets wider, and a larger proportion
of the estate population resides in the salt front pastures. (Lnsignan, Enmore,
Non Pareil).

On the West Coast of Berbice the land is low, and the sea defences less
efficient ; sea water in many points invades lands situated south of the public
road and railway. These are the healthiest coastal localities west of the Berbice
Estuary (Lichfield, Bush Lot, Hopetown).

At Bath, the only sngar estate on this section of the coast, between 1934
and 1937, the spleen rate averaged only 8.6, and in 1937 it was as low aB 1.5%.

On the Corentyne Coast, as an average, the climate is drier ; the locality is
notorious for its constant and high breeze. The width of the salt belt runs into
miles ; the rice fields lying south of the public road are salt and windswept ;
tree vegetation is very scanty and poor. At Albion and Skeldon the cane
cultivation borders on the yards ; at Port Mourant nearly 3 miles of rice lands
separate the cane cultivation from the estate village. The Corentyne Coast is
usually free from endemic malaria.

Diagram No. 1 shows the distribution of malaria, as indicated by the spleen
rate, throughout the Guiana Coast — between the Essequibo and Corentyne
estuaries — at the end of 1937 ; the tendency of the rate to fall progressively
from west to east is well shown. The average rainfall also shows a Bimilar
tendency, there being a difference of no less than 33 inches between the West
Coast of Demerara and the Corentyne. No data are available as regards atmos-
pheric humidity and air velocity for a comparative study of these factors
throughout the coast ; the meteorological observatories of Georgetown and New
Amsterdam are both situated on river estuaries. From general experience we
believe it is safe to assume that the Corentyne coast is both drier and windier.

It is usually believed in the Colony that the right bank of the river
estuaries (Demerara and Berbice) is healthier than the left, and our findings
tend to confirm this belief to some extent. On the estuaries, in general, con-
ditions appear to be more favourable than on the coast for the breeding of
.4. darling i , as the land is relatively higher and less salt, the cane cultivation
extending nearly to the river banks. The night atmosphere is also damper, and
morning mists are frequent ; malaria tends to be highly endemic.

Diamond Estate — on the right bank of the Demerara River, some 11 miles
from its ' mouth — and, to some extent, the village areas situated to the sonth of
this plantation form a very notable and interesting exception which we are at
present investigating.

The distribution and incidence of malaria throughout the edast, as shown
in diagram 1, can be accepted as what usually obtains under average conditions,
but, occasionally, at intervals of 10 or more years, with a general exacerbation
of malaria throughout the Colony, severe epidemic outbreaks occur also in

6 AG&tCultfTJRAL JOtmNAL 6 $ fiEIttSfl OtTUtfA (X 1.

localities whioh are usually free from the disease) notably on the Oorentyne
Coast. Similar outbreaks were observed in 1926 and 1938 : both these epidemics
we ascribe to abnormal meteorological conditions which prevailed during those
years, which favoured the breeding of A. darlmgi even in localities where this
species is usually not found.

Let us now briefly examine which are these meteorological factors which
favour the multiplication and dispersion of A. darhngi and thus give rise to
malarial epidemic outbreaks.

Diagram No. 1 shows the average rainfall at various points along the coast
at Uitvlngt (1916-36), Ogle (1906-36), La Bonne Intention (1916-1936), Enmore
(1913-1936), Bath (1900-37), Albion (1865-1936 A Port Mourant (1880-1936), and
Skeldon (1906-36).

These averages, from our particular point of view, bavo relatively little
value, as the annual range of deviation is very considerable and irregular. In
table I the annual rainfall at Bath Estate, from )900 to 1938, is shown as an
example. One notes that the annual rainfall varied within the extromo limits
of 51.83 inches in 1913 and 128.46 inches in 1938.

Table I.

Annual Rainfall at BtTii, West Coast, Berbice, 1900 — 1938.

Ymr

RmnfaJI
ni nidus

Ytur

Rainfall
in indus

1900

85.56

1920

53.12

1901

61.29

1921

74.34

1902

76.38

1922

84.45

1903

92.83

1923

72.04

1904

57.72

1924

74.32

1905

65.73

1925

52.03

1906

89.48

1926

54.17

1907

93.74

1927

104.74

1908

73.94

1928

76.86

1909

66.29

1929

79.08

1910

84.07

1930

83.52

1911

—

1931

69.84

1912

67.53

1932

98.29

1913

51.83

1933

115.30

1914

55.04

1934

67.99

1915

77.25

1935

95.02

1916

89.91

1936

104,35

1917

81.64

1937

87.28

1948

1919

68.38

1938

128.46

72.08

Annual Average 77.17 inches

Annual Maximum (1938) 128.46 inches
Annual Minimum (1913) 51.83 inohea

PtiATB I

Platb II.

RAINFALL

INCHES.

MALA HI A
CASES.

Months- I II III IV V VI VII vm IX X XI XII

Ffglrc 2. — Iii the tidal river districts of the interior August and September are usually
dry months ; the seasonal character of malaria is more distinct than on the coast, as the breed-
ing of the carrier, A. darliw/i, is mainly dependent on the early summer rains. In 1926 a severe
drought was experienced during the Miree months of the year, but heavy rains followed
lasting from May to September with abnormally high atmospheric temperature. A . darlifyjt
appeared in very large numheie and a severe malarial epidemic resulted which affected these
districts for the following two years. Our graph illustrates the trend of the rainfall and
malaria incidence cmves as registered at Mackenzie, on the Demerara River, in 1926.

MALARIA Iff BRITISH GUIANA*

The total annual rainfall hag relatively little importance from a malario-
logioal point of view ; we find, for instance, that malarial epidemics occurred
both in 1926 and 193ft with rainfalls of 54.17 and 128.46 inches respectively ;
conversely in 1933 with a rainfall of 115.30 inches no epidemic was observed.
The seasonal distribution is ivhat matters .

Heavy atmospheric precipitation during the late autumn and winter
months, when the atmosphere is cooler and the trade winds strongest, is never
associated with an increase in the number of Anopheles ; on the contrary, such
rains appear to influence adversely these insects, and their number rapidly falls,
the minimum incidence being observed in February and March.

The incidence of malaria invariably declines during October, November
and December, the healthiest months in this respect being February, March and
April. The exceptionally heavy rainfall in December of 1933 and January,
1934 which caused disastrous floods did not produce any appreciable lise in the
incidence of Anopheles and consequently of Malaria.

Failure of the autumn-winter rains is undoubtedly favourable to the
survival of Large numbers of .1. darhngi ; a drought at this season is often the
prelude to a malarial epidemic later in the year.

The spring-summer rainy season which usually comes on in May and
coincides with the period of highest atmospheric temperature and with the fall
of the trade winds, always gives rise to active Anopheline breeding. If these
rains are steady and continue throughout July and August, and possibly into
September, especially if the temperature is unusually high, the breeding of
A dnrhngt becomes both extensive and intensive, and the incidence of malaria
rapidly rises.

In localities which are usually free from malaria, and where under normal
or average conditions, the physio-chemical properties of the surface waters are
such as to render them unsuitable for the breeding of A . darlnu/t , the diluting
action of heavy and persistent rains may so alter their characters as J;o transform
them into attractive and productive breeding sites. During heavy rains, in
July 1938, we found, for instance, A. Atlntarsis, usually an inland savannah
species, abundant and breeding actively in rain water collections situated
outside the sea wall at Bel Air.

Observations carried out in the interior, on the Demerara River (1923-
1932), indicate that the duration of the period intervening between the onset of
the rains and the rise in the incidence of malaria varies in inverse proportion
to the height of the atmospheric temperature. A high temperature speeds up
both the development of the Anopheles from ovum to adult, and the evolution
of the malaria parasite in the Anopheles, />., Anopheles breed more rapidly and
become infectious in a shorter period after feeding on a suitable malarious
subject

AORlOTOTtriUL JOURNAL OF BRITISH OTUHiU

[X, L

Increased nocturnal atmospheric humidity, which accompanies persistent
rains, will favour the survival and flight of A . darlingi and thus increase its
activity and dispersion,

Tho ubiquitousness of favourable surface waters — resulting from heavy
and persistent summer rains — in close proximity of houses and villages, will
greatly reduce the hazards which the Anopheles must face in its long flights to
and from its habitual breeding sites, as they will lav their eggs in the nearest
suitable waters and return to the houses repeatedly to procure the blood meals
they require ; a larger proportion of malaria infected Anopheles will, therefore,
survive in close proximity of human habitations, and the transmission of malaria
inevitably becomes extremely active.

This is the mechanism by which the malarial epidemics of 192(1 and 1938
originated both on the coast and in the tidal river districts of the interior.

Diagram II illustrates relations between malarial (incidence and rainfall at
Mackenzie in 1926.

Diagrams III and IV refer to the malarial epidemics at Skeldon and Bath
in 1937 and 1938.

The chronological sequence of the 1938 epidemic outbreaks in Berbice is
of special interest : Skeldon, which is situated some 8 miles up the Corentyne
estuary, was the first affected ; it suffered a mild epidemic in 1937 and again a
severe outbreak commencing m June 1938. Albion was the next affected ; It
suffered both in 1937 and 1938. This plantation is situated farther inland than
the next, and the yards border on the cane cultivation and on sheltered bush-
surrounded rice fields. Port Mon rant, which lies further north, in open
country, suffered mild epidemics coming on late in August in both years. Bath
was only very slightly affected in 1937 and was the hist to be involved in 1938.
Ihe outbreak on this coastal estate was sharp and short ; A* darlingi which
was extremely abundant in October had practically disappeared in January.

Malaria, a alike other epidemic diseases, cannot spend itself in the oonrse of
a few weeks or months ; once the infection is acquired, the disease evolves by
relapses; even with the complete disappearance of the Anopheline carrier, the
consequences of an epidemic continue to be felt for two or three years. Thus
the localities of the Corentyne Coast which in 1937 had spleen rates of 2 or 3%
now have rates of 32 and 24% ; in another locality of the west coast of Berbice,
the rate has risen from 1 .5 in 1936 to 20.8% in 1938.

^If we refer again to Table I, we observe a tendency in the annual rainfall, as
registered at Bath, to increase during late years ; whereas from 1900 to 1926
atmospheric precipitation reached 90 inches p.a., on only two occasions (1903 and
1907) the maximum recorded being 93.74 inches, from 1927 to 1938, this has
occurred no less than 6 times with 104 inches in 1927 and 1936 ; 115 is 1938 and
128 in 1938. *

MALARIA IK BRITISH GUIANA.

If this tendency persists malaria will undoubtedly become endemic in many
localities which up to the present have enjoyed a remarkable freedom from this
disease. This is particularly probable for the West bank of the Corentyne
estuary, where the higher level of the land, the low soil salinity, the less active
ventilation, the higher atmospheric humidity, the abundance of rice and cane
lands coupled with the abundance of bush and tree vegetation, are all conditions
of themselves favourable to the presence of A. darling i.

PART V. WHAT MALARIA MEANS TO THE RURAL POPULATION

OF THIS COLONY.

The great majority of the rural inhabitants of British Guiana pass their
whole existence exposed to the ravages of malaria ; they accept the disease as an
inevitable neoessity. There exists no trace of popular instinct or tradition aiming
to avoid the disease by intelligent location of settlements and villages as is
usually found amongst indigenous populations of malarial countries.

In the interior only the Aboriginal Indian builds his camp en high ground,
on sand or gravel ; the immigrant from the coast, of negro, Chinese, Portuguese,
east indian and mixed race, invariably settles and builds his house on the alluvial
and intensely forested and malarial mud fiats which form the floor of the river
valleys.

Such a state of affairs is comprehensible when we consider that the mass of
the present day population of the Colony descends from people brought to the
country in the past to fill the requirements of the plantations (cotton, coffee,
cocoa and sugar) which have always been the main raison d'etre of the Colony.
These people were made to settle on the fertile alluvial plains, and trained to live
where they were required. The habit so formed, in the presence of the very
peculiar configuration and hydrological regime of the coastlands, has given rise
to a rural population of somewhat amphibian customs !

Amongst the more educated classes, both in the country and towns, ordinary
practical knowledge about malaria is remarkably deficient ; one notes a frequent
tendency to camouflage the disease under other names suoh as “low fever,”
“ biliousness,” etc.

Public opinion in general appears definitely apathetic to Malaria which
involves scores of thousands of people and causes> directly or indirectly, thousands
of deaths every year, whilst it has shown considerable enthusiasm in relation to
suoh relatively minor health problems as tuberculosis and leprosy which cause
only an infinitesimal fraction of the mortality, disability and financial loss for
which malaria is responsible every year.

It may, therefore, be of advantage to conclude this series of articles»by the
study of certain statistical data we have collected, which vividly demonstrate
what malaria r eall y means to a large section of our rural population and to the
Colony In general ; and what account must be taken of this particular problem
ip sh e fra mi ng of any plan or scheme for land settlement and further agricultural
development?

AGBIOT7LTTTRAL JOUSNAL OF BRITISH GUIANA.

tx 1.

Oar studies have been limited to the population of the sugar estates, which,
in 1937 aggregated olose on 68,000 persons, i.e., 35% of the total coastal rural popu-
lation of the counties of Demerara and Berbice. There is no reason to believe
that conditions in the villages in the Bame areas are in any way better ; the
oontrary is more probably the truth, as the villagers, whilst living in localities
similarly and often less favourably placed, do not enjoy the advantages of estate
residents in the form of free hospital and medical treatment. The sugar estates,
in this connection during the last ten years have spent an average of close on
$104,000 per annum on their hospitals only.

In 1938 the sugar estates issued free of charge no less than 422 lbs. of
quinine, i.e. 27% of the total amount of this drug imported into the Colony in
1937.

Dr. Boyd’s recent survey tends to confirm our surmise ; one of the highest
spleen rates in the Colony was recorded from Lodge Village on the outskirts of
Georgetown, and high rates were observed in villages on the East Bank.

It is very difficult to obtain a correct idea of the damage done by malaria from
an analysis of morbidity and mortality returns ; the ^reat majority of fever
cases pass unreported and a great many more are incorrectly diagnosed. Malaria
often causes death in its acute form ; most of such deaths are undoubtedly
registered under the correct diagnosis, but the highest mortality is caused by
chronic malaria which entails extensive and varied organic degenerative pro-
cesses ; the clinical picture is complicated and a great many such deaths are
registered under diagnoses obher than malaria, as for instance, cachexia, maras-
mus, dropsy, nephritis, debility, senility, etc.

On the sugar estates, an average of 125 out of every 1,000 deaths registered
are directly ascribed to malaria ; that, in itself, constitutes an alarmingly high
rate.

The trend of the vital index ( 1 'curve, i.e. the ratio of births to every 100 deaths
registered per annum, studied in relation to the incidence of malaria, as indicated
by the spleen rate, furnishes, we believe, the most reliable index as to the effect
of endemic malaria on a community.

We have carried out such an investigation on all the sugar estates of the
Colony from the year 1920 to 1937, classifying them in 3 groups (A, B and C)
according to their spleen rate as determined in 1937, i.e. before last year’s
epidemics.

Diagram No. V refers to 5 estates (group A) aggregating a population of
20,967 (Plantations Diamond, Bath, Albion, Port Mourant and Sheldon) all of
which, under average conditions, are practically free from endemic malaria. In
1937 all these estates had spleen rates ranging from 0.1 to 5%.

<lj The term “ Vital Index ’’ has been suggested by Pearl “ to designate that measure of a
population’s condition whioh is given by the ratio of births to deaths within a given time.”
Of this%idex this Author states : ‘‘It may fairly be said that there is no other statistical
constant which furnishes so adequate a picture as this of the net biological status of a popula-
tion as a whole at any given moment.” And again : “ After much stnay of it 1 am coni meed
that no single figure gi\ es so sensitive a measure of the vitality of a nation or any sub group
of people as this does.” R. Pearl Introduction to Medical Biometry und Statistics.— 1923,

Plate V.

Diagram V. — In this and the tvo following diagrams, which should l»e carefully com-
pared, tlio Vital Index or births to deaths ratio, is studied from 1920 to 1937 over the* whole
sugar estate population, classified into three groups according to the incidence of malaria ns
indicated by the spleen rate.

Y* 1 ® 100-100 base line indicates 100 deaths ; the graph shows the number of births for every
100 deaths registered per annum. When births exceed deaths, the graph runs above the
base line ; when births are fewer than deaths, then the graph falls below the base line, (see
diagrams VI and VII).

The above graph shows the trend of the crude Vital Index on a group of five sugar estates
aggregating a population of 20,907, which are free from endemic malaria. As a yearly average
from J920 to 19B7 there were 244 births to every 100 deaths, births being constantly and
considerably m excess of deaths.

The average annual infant mortality (I.M.) waB 113 per 1,000 live births.

PLATE VI

1920 ltrjl lt>22 3923 1924 192' 1926 1027 1928 3929 1930 1931 1932 1933 1934 1935 1936 1937

Diagram VI. — Crude Vital* Index curve, 1920-1937, from a group of 10 Sugar Estates,
aggregating a population of 29,832, which are subject to endemic malaria, (spleen rate from
5 to 30%). As an average for the whole period there were 152 births to every hundred deaths.
In two years there were more deaths than births. The average annual Infant Mortality
(LM.) was 155.9.

MALARIA IN BRITISH GUIANA.

Throughout the 18 year period covered, the number of births on these
estates was constantly and very considerably in excess of the number of deaths ;
as an average there were 244 births to every 100 deaths. The curve has a very
marked upward trend. In the early part of 1920 a severe epidemic of malaria
swept the Colony (see Diagram II) ; it appears likely that this epidemic was
connected with the fall in the vital inder which occurred in 1927 and 1928. In
that case we may expect to witness again a similar fall during 1939 and 1940
as a result of last year’s epidemics.

Diagram No. VI illustrates the vital index curve from 1920 to 1937 for 10
estates (Group B) aggregating a population of 29,832 (Plantations Uitvlugt,
Leonora, Versailles, Providence, Farm, Vryheid’s Lust, Non Pareil and Enmore)
which are subject to endemic malaria, with spleen rates not exceeding 30%. We
observe that the general level of the curve has fallen very considerably (compare
with Diagram V). In two years, 1922 and 1923, there were actually more deaths
than births and in 1928 the two just balanced. As an average, for the whole 18
year period, there were 152 births to every 100 deaths, i.r. a fall of 92 births from
the average shown by the non-malarial estates included in Group A.

Diagram No. VII gives the vital index curve from 1920 to 1937 for 7 sugar
estates (Group 0) aggregating a population of 15,870 (DeKinderen, Wales, Ogle,
La Bonne Intention, Lusignan, Blairmont and Providence, Berbice) on all of
which malaria is highly endemic the spleen rate being constantly above 30%.
The curve shows a fall to yet a lower level when compared to the two preceding
diagrams and in the years out of 18 (1921, 22, 23, 28 and 1933) there were more
deaths than births. For the whole period, as an average, there were only 119
births to every 100 deaths, t.e. a decline of 125 births on the average of the non-
malarial estates included in Group A.

In Table II we present certain other vital statistical data, referring to the
1932-37 period and to the sugar estate population of the whole Colony classified
according to the spleen rate, as above, into 3 groups, A, B, and C.

Table II.

Malaria Rate in relation to birth rate, maternal mortality, infant
mortality, and stillbirth rate, annual averages 1932 — 1937.

Estate Group

Population

20,907

29,832

15,870

Spleen Rato

Under 5%

5% to 30%

Over 30%

Average Annual Birth Rate

32.1

25.0

20.7

Maternal Death Rate

10.6

21.4

21.2

Infant Mortality

113.0

155 9

170.9

Stillbirth Rate

* 92

These figures indicate

that the population

of the malarial

areas is less

fertile as showij by the decline of the birth rate in parallel with the increase of
the spleen rate.

12 AGRICULTURAL JOURNAL OF BRITISH GUI AHA, [X, 1.

The hazards of child bearing are similarly increased as shown by the twofold
rise in the maternal mortality and the stillbirth rate in gronps B and C.

The chances of survival of the infants decrease as the malarial rate rises ; the
same could be said for young children between 1 and 4 years of age.

These diagrams aud statistics indicate most clearly how deeply malaria
affects a population ; its ravages are not limited to the morbidity and mortality it
determines; the very vitality of the community is involved and its normal
tendency to reproduce and expand inhibited. Such a loss of vitality inevitably
reflects itself on the productiveness, *>. on the economic value of both the indivi-
dual and the community.

In British Ouiana, with its peculiar geographical, climatological and excep-
tional hydrological conditions the malarial problem, as we have shown, presents
itself as one of unusual magnitude and with characters which are probably
unique ; it is intimately connected with the two basic agricultural industries of
the Colony.

In spite of such difficulties we feel confident, bn the base of our findings,
which have revealed certain limitations in the biology of A. dnrlingi which may
be exploited to its detriment, that malaria can be successfully controlled if not
eradicated in a considerable portion of the inhabited coastland of this Colony.

Plate VII*

Diagram VII.— Crude Vital Index curve, 1920-1930, from a group of 7 Sugar Estates,
aggregating a population of 15,876, which are subject to severe endemic malaria (spleen rate
30 to 60%). As an average over the whole period there were 119 Liuba to every hundred
deaths In five years there were more deaths than births* The average annual Infant
Mortality (I,M.) was 170.9 per 1,000 live births.

RESULTS OF PADI VARIETY TRIALS, 1938

P. A. Chan-Ciioono, b.sc., a.i.c.t.a.

Assistant Plant Breeder, Department <>J Agriculture.

Introduction.

In the Agricultural Journal of British Guiana, Vol. IX, pp. 98— 9i>, an
account was given of the variety trials which were laid down for the 1938
Autumn Crop. Fifteen of the older varieties which had been tested in previous
years were retained, some to be used as controls, others to be given a final test.
Thirty -four varieties which had passed through the progeny rows at the
Georgetown and Henrietta Experiment Stations, for purification and preliminary
yield testing, were considered promising enough for trials ; seven of these were
hybrids bred at the Georgetown Station. Three varieties found in mixed
cultivations in the Corentyne District, were also included.

The sites of these variety trials were as follows :

Berbiee: Whim Under the supervision of Mr. J. D.

and Gillespie, Agricultural Superintendent,

No. 70 and later, of Mr. E. M. Morgan, Asst.

Agricultural Superintendent.

W/0, Berbiee Under the supervision of Mr. E. M.

Morgan, Asst. Agricultural Superinten-
dent.

Demerara: Georgetown Rice Under the supervision of Mr. E. M.

Station. Peterkiu, Agricultural Superintendent.

Vreed-en-Hoop Under the supervision of Mr. E. G.

Benson, Agricultural Superintendent.

Ejsequibo : Henrietta Under the supervision of Mr. A. A.

Abraham, Agricultural Superintendent.

Two classes of trials were laid down — Class -^A (Standard) and Class B
(Individual District). The purpose of the Standard trials was to test the more
promising varieties in all the districts, while the Individual District trials
contained certain additional selected varieties whioh it was considered desirable
to test in different districts.

Crass A (Standard) Trials.

Six Class A trials, two of long-grained varieties and four of medium-grained
varieties, were laid down at each of the stations Georgetown, Henrietta and
Whim. Long-grained controls (Demerara Creole and D 221) and medium-grained
controls (D 99 and D 114) were included in each group. Unfortunately at Whim,
the water supply failed at flowering time, so that five of the trials had to be
discarded on account of the very poor or no yields obtained.

The trials consisted each of five randomised blocks, containing nine, ten
or eleven varieties in each block.

The results are presented in Tables I and XI.

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 1.

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1 RESULTS OE PADT VARIETY TRIALS, 1938

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16 AG&ICffLTtTBAL JOtTMUt Of BRITISH GtJtAHA* £X 1.

In the six trials at Georgetown, shown in Table I, the following revolts
were obtained :

Trial 1 : The four leading varieties are D 114, D 99, D 259 and Jaisingh.

The remaining six varieties are significantly inferior, except
Kalyaman which is inferior to D 114 only.

Trial 2 : This trial yielded no significant result.

Trial 3 : D 99 was easily the leading variety, while D 108 was definitely
the worst. Unity and D 162 were very nearly significantly
inferior to D 99, but were not superior to the rest.

Trial 4 : Apart from D 262 and D 261, which were definitely the worst
varieties, there was very little to choose between the varieties in
this trial.

Trial 5 : I) 257, D 256, D 99 and D 111 were definitely better than the last
five varieties in the list. Demerara Creole and D 246 were
significantly inferior to the remaining nine varieties.

Trial 6 : This trial yielded no significant result.

From the variety trials at Henrietta, shown in Table II, the following
conclusions may be drawn :

Trial 1: The leading varieties were D 99, D 111 and Jaisingh, these being
significantly superior to the rest, except D 259 which was
exceeded only by D 99.

Trial 2 : D 99 was sig lificantly superior to D 114, which in turn was
significantly superior to the rest. Kalyaman, Nickerie Patna and
D221 followed with significant superiority over the others.

Trial 3 : D 99 again proved the best variety. D 94 and D 1 14 came next,
but D 94 alone was significantly superior to D 109 and D 162.

Trial 4 : D 99 and 114 led in this trial, both being significantly superior
to the others. No. 79 and D 258 showed no difference between
themselves, but both were significantly superior to the rest.

Trial 5 : D 99 once more came ahead of the other varieties. The remainder
were bracketed together, with the exception of Demerara Creole
and D 221 which were significantly the worst.

Trial 6 : D 99 led again, with D 114 and 19 — 37 coming second, both
proving significantly superior to the rest.

The one Class A variety trial from Whim (a trial with medium-grained
varieties) gave the following results :

MRUWa OP P\Dl VARIETY TRIALS 1938,

Table III.

Variety

Yield per acre
lb.

D 255

4,244

D 256

3,812

D 221

3,708

Demerara Creole

3,568

I) 247

3,512

D 114

3,108

D 246

3,048

D 116

2,816

D 250

2,416

11 99

2,238

Sig. Dill. P — .05

523

D 255 and D 256 were the leading varieties,

1) 221, Demerara Creole and

D 247 followed, bat only D 221 was significantly
varieties.

superior to the remaining

Clvss B (Individual District) Trials.

These trials were laid down at Henrietta (Esseqaibo), Vreed-en-Hoop

(West Demerara) and No. 70 and W/C, Berbice (Berbice). The trial at Henrietta
contained selected long-grained varieties, tested against D 114 as control ; the
trial at No. 70 contained old varieties and three varieties local to that district.

The results are shown in Table IV.

Table IV.

AG&ICULTXTRAIj JOURNAL OF BRITISH UtflANA.

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BBSUI/TS OF PADI VABIBTY TBIALS, 1938.

From these, the following conclusions may be drawn •

Trial 1 : At Henrietta, the first five varieties, 1 — 1, D 114, 18 — 4, Seymour
S, and 25 — 5, showed no significant difference between themselveB,
but of these, 1—1 alone was significantly superior to the six last
varieties in the list. Sue was definitely the worst variety.

Trial 2 : At No. 70, there was no significant difference between the first five
varieties, D 97 B, No. 79, D 114, Benab No. 79 and Kalyaman, but
D 97B was significantly superior to the last five varieties listed.

Trial 3 : The trial at W/C, Berbice yielded no significant results.

Trial 4 : At Vreed-en-Hoop there was equality among the first four
varieties i) 1 14, Jaisingb, D 99 and I) 110 : of these D 114 alone
was significantly superior to the five varieties at the end of the
list.

Conclusions,

A consideration of the present results and those obtained in previous years
leads to the following general conclusions :

1. Judged from the yield standpoint only, D114 is the best of all the
varieties available. If certain milling difficulties can be overcome this
variety will prove very valaable to grower and producer alike. It has
been compared with Demerara Creole, No. 79 and Blue Stick on many
occasions with the following results :

In 42 trials it ontyielded Demerara Creole by 404.3b lb. per acre.
,, ,, ,, ,» No. i 9 ,, 31s. sO ,, ,, ,,

,, Is ,, ,, ,, Blue Stick ,, Jbh.lw ,, ,, i,

2. No well-tested long-grained variety as yet offers as a substitute for
Demerara Creole.

3. D 99, D 109 and D 110 are heavier yielders than the standard
medium-grained varieties No: 79 and Blue Stick, and are worthy of
commercial consideration. In the meantime they are being examined
as to drought resistance, a characteristic of No. 79. D 99 has a longer
vegetative period than No. 79.

4. The following varieties should be tested further :

Long-grained .

Mcdi u m-gra i n ed.

D 11(5 D 94

I) 253 D 1152

D 254 1) 246

D 259 D 247

29-37 D 250

Jaisiugh D 255

Nickerie Patna D 256

1) 257
Unity

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[X, 1.

5. The following varieties may be dropped from farther trials : —

D 91

D 251

15-37

Padi Berbice

D 108

D 258

17-37

Seymour

D Ho

D 2G1

18-37

Kalyaman

D 193

D 262

19-37

D 221

13-37

23-37

Acknowledgment.

Thanks are due to the Director of Agriculture, the Deputy Director of
Agriculture (Acting)and the Sugar Agronomist and Plant Breeder lor their views
and suggestions as to the presentation of these results.

RESULTS OF RECENT EXPERIMENTS WITH SUGAR CANE

C. HOLMAN B. WILLIAMS, M.A., a.i.C.t.a., Dip. Agr.,

Sugar Agronomist and Plant Breeder,

Department of Agriculture .

The results of a large number of variety and manurial trials with cane,
harvested during the last six months of 1938, have been printed in an
abbreviated form and distributed locally to sugar estates and managers and others
intimately connected with the industry. The data will appear and be fully discussed
in Sugar Bulletin No. 8 , which is due to be issued about July, and will deal
with the experiments harvested during the year ending June 30. In the
meantime, however, attention may be drawn to some of the points which have
emerged.

Of the canes which have been harvested as plants, first and second ratoons,
Co. 213 has been well tested and considerable reliance can be placed on its
position with regard to the standard canes. Some estates are making commer-
cial tests of this cane* which appears to be an economic sugar produoer, and
others are advised to do likewise. D. 49/30 and D. 66/30 have also been fairly
well tested. Though neither is likely to outfield P.O.J. 2878, the former
may be expected to out yield Diamond 10. More experimental data are being
sought from P.O.J. 2753, D. 50/30, D. 75/30, D. 67/30 and D. 150/30 which ail
continue to show promise. In the meantime nurseries of these canes should be
established and extended.

D. 419/33 (Co. 281 x Diamond 10) heads the list of canes reaped only as
plants and first ratoons. It has been harvested twice as a plant and once as a
first ratoon and promises to be satisfactory both as regards cane yield and juice
quality.

Of the seedlings harvested in plant cane trials only, D. 552/33 (D. 219/30
x Diamond 10) and D. 166/34 (P.O.J. 2878 x Sorghum) are worthy of note. The
former, in a single test, gave eight tons of cane per acre more than P.O.J. 2878
and a juice just slightly inferior to that of the standard. D. 166/34, a variety
which has been outstanding in the nurseries at Sophia, has given the following
average plant cane results in two experiments (La Bonne Intention and
Leonora) where it was compared with Diamond 10 :

Variety,

Cano,

Tons/acre.

Sucrose,

% Cane.

Glucose

Ratio.

Juice

Purity.

Sucrose,

Tons/acre.

D. 160/34

48.07

14.02

7.22

88.0*

7.11

Diamond 10

39.94

14.00

0.53

90.1

5.82

AGRICULTURAL JOURNAL OF BRITISH GUIANA,

[X, 1,

The fertiliser results may be summarised as follows

1. Further confirmation is reported as to the sulphate of ammonia require-
ments of frontland, /.<?.* 2 cwt. per acre for plant canes and 4 cwt. each *
for first, second and third ratoons. Increased evidence is available in
support of much heavier dressings of nitrogen (probably of the order of
120-140 lb. per acre for both plants and ratoons) for pegassy clays and
such applications are likely to yield a profit. If, however, they are given
in the form of sulphate of ammonia (5-6 cwt. per acre), a dressing of
one ton of limestone at every replanting seems essential if the useful
life of these already very acid soils is not to be endangered.

2. Nicifos (18 : 18) was tested on first ratoons at five pegassy clay sites
and on plant canes at four frontland sites. It increased first ratoon
yields in Field 36 S.D., Cane Grove, where it had had an excellent
effect in the plant canes, and the total difference in its favour for two
crops is impressive. The area is deficient in phosphate and the result
is probably due to none ol the other fertilisers being accompanied
by phosphate. Thus in Field 10 0., Wales, where both trial sites
were somewhat deficient in phosphate, it did not differ significantly
from nitrbchalk plus basic slag in effect on the plant canes or
first ratoons. Similarly in Fields 64 and 70 Z., Uitvlugt, it was
not better than nitrochalk plus basic slag for plant canes and on first
ratoons it proved inferior in Field <54 Z and of equal merit in Field
69 Z., Uitvlugt. Nicifos was compared with sulphate of ammonia and
nitrochalk four times with plant canes on frontland. It did not produce
a significantly different yield in any instance but at Leonora the canes
from the nicifos plots were sweeter than those from the sulphate of
ammonia plots but not than those of the nitrochalk treatments.

3. Nitrochalk was tested with first ratoons five times on pegassy clay and
with plants four times on frontland. On the pegassy clay the yields did
not differ statistically from those given by nitrogen-equivalent dressings
of sulphate of ammonia, thus confirming the plant cane results where in
only one out of five instances was there any difference. Further, in com-
bination with basic slag, it proved as efficient or more so than nicifos for
both plants and ratoons. On frontland there was no significant difference
between the effect of nitrogen-equivalent dressings of nitrochalk and
sulphate of ammonia on plant cane yields. At Leonora, however, nitro-
chalk gave a definitely sweeter cane than sulphate of ammonia.

It has been proved that the cane soils of the Colony are rapidly
becoming more acid and that the process is accelerated by the increased
Hie of sulphate of ammonia. On the other hand, it is clear that heavy
nitrogen applications are economically sound and the compromise has
been suggested, and largely adopted, of supplying the nitrogen in the

RBftULTa OB' RECENT EXPERIMENTS WITH SUGAR CANE.

form of sulphate of ammonia and applying a dressing of one ton of lime-
stone per acre at each replanting to counterbalance the acidifying effects
of the sulphate of ammonia.

A possible alternative procedure would be to employ a nonacidify-
ing nitrogenous manure, and it now appears that nitrochalk is deserving
of careful consideration and commercial tests by the sugar estates. This
manure contains a lower percentage of nitrogen than does sulphate of
ammonia and more would have to be used to obtain a nitrogen-equivalent
dose, the proportion being roughly four of nitrochalk to three of sulphate
of ammonia. Since the two fertilisers are quoted at approximately the
same price per ton in England, it follows that the ratio of cost would
also be in like proportions. On the other hand yields are the same from
nitrogen-equivalent doses of the two fertilisers and at iirst one may be
tempted to forego what appears to l>e a considerable increase in cost (3 : 4)
for no immediate gain. If, however, consideration is given to the fact
that with the sulphate of ammonia one should buy and apply a ton of
limestone at every replanting whereas the nitrochalk will not acidify the
soil but, on the contrary, supply it with a considerable amount of calcium
carbonate, tho true increase in cost from the use of nitrocualk will be
seen to be negligible.

It is suggested that each estate take snyrdf fields through a complete
cycle using only nitrochalk as a nitrogenous manure, and that where the
estate possesses both soil types several fields in each area should be so
treated.

1. Nitrate of soda appeared in five first ratoon trials on pegassy clay. In
the plant canes it had not given statistically different yields from
iiitrogen-equivalent doses of sulphate of ammonia or nitrochalk. In the
first ratoons it proved equivalent to sulphate of ammonia in all five trials
but was definitely inferior to nitrochalk in one out of the five (Field 36
S.l)., Cane Grove). Oil the whole -it seems a Jpss likely substitute for
sulphate of ammonia than does nitrochalk.

5. Superphosphate of lime had no effect on the yield of first ratoons (Field
2011.) at Port Mourant but had a definitely adverse effect on juice purity.
It will be remembered in this connection that a medium dose of this
fertiliser had an adverse effect on tho sucrose content of the plant canes
in Field 23 R., Port Mourant. The plots in this field were tested as first
ratoons for any residual effoct of the plant cane pliospbatic dressings but
there was none. Phosphatic applications cannot be advised for this
portion of the estate. On second ratoons, superphosphate of lime had no
effect in Field 81 R.H., Rose Hall, but a medium dose definitely increased
cane yield in Field 26 lip., Blairmont. As in the case of sulphate of
potash there was no effect on yield in the two earlier crops and the
present jesult appears to be the cumulative effect of three dressings.

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

tx, 1.

6. Sulphate of potash had no significant effect on second ratoons on
frontland at Rose Hall (Field 81 R.H.,) but gave a definite increase in
second ratoon yield on Field 26 Rp., Blairmont. In the latter field there
had been no effect on plant cane or first ratoon yields. It seems that the
present result is the cumulative effect of three applications and that
potash-fixation by the soil may be involved. On first ratoons at Port
Mourant there was no residual effect from plant cane applications (Field
23 R.) or from applications to first ratoons only (Field 20 R.)

7. Manganese ore, from a local deposit, was tested on a pegassy clay. It
had no definite effect on the plant cane yield but adversely affected the
juice purity.

CATALOGUE OF THE LEPIDOPTERA RHOPALOCERA
(BUTTERFLIES) OF BRITISH GUIANA

ARTHUR HALL, F.R.Ent.s.

Introduction.

British Guiana is, with the exception of India, the richest of all the British
Dominions in Lepidoptera, but it is remarkable how little has been written
about them. When attempting to obtain information on the subject previous to
my first visit to the country in 1929 I was only able to discover isolated records
of the butterflies scattered through all sorts of books and periodicals
of various dates covering more than a century. Many of the species
described by the older authors with such vague localities as “ Guiana ”
and “ South America*’ may have come from our Colony, and the very large
number recorded and figured in the classic work of Cramer as long ago as
1 779-1791 from the neighbouring Dutch settlement of Surinam gives some idea
of what we may expect to find in British Guiana. But the very few competent
entomologists who have visited the latter country have contented themselves
with collecting specimens without leaving any account of their expeditions and
in view of the rapidly increasing number of scientific travellers who now
come to British Guiana and the great importance recognised as attaching to
geographical distribution and variation it has been thought that a preliminary
Catalogue of the Rhopalocora known to inhabit the Colony is desirable. As one
would expect from the nature and situation of the country the butterfly fauna
of British Guiana is mainly that of the great Amazonian Region with a slight
but distinct admixture of Venezuelan elements. It has, however, a number oi
interesting peculiarities of its own. A feature which it shares with the lower
Amazon is the great abundance of sprrtrs as compared with the comparatively
small number of individuals. Migratory swarms of such species as Colon#'! ta
statiro and the moth Urania leilas are not infrequent, especially "along the
rivers but with these exceptions one rarely meets with those large masses of
butterflies so often to be seen in hilly districts even in temperate regions and it
is sometimes possible to walk a mile or more in the Guiana forest without seeing
any butterflies at all except perhaps a few small Satyridae . On the other hand
in favourable localities the collector can easily obtain over a hundred species
within two or three days and hardly a day passes without yielding something
which he has not met with before. Although the fallowing catalogue includes
well over seven hundred species the fact that many species, particularly of the
smaller kinds, which are known from Dutch Guiana have not yet been recorded
from our side of the frontier renders it certain that many more remain to be
discovered an<^ inasmuch as the whole southern half of British Guiana from

26 • AGftteULfnftAL JOTjENAL OP MMHlf QUIAJRA. It, 1.

Tamafcumari to the Brazilian frontier is practically unexplored by the lepidop-
terist, it would not be surprising if the number of butterflies occurring within the
Colony should ultimately be found to exceed one thousand species. In a
country having a land frontier on three of its four sides and without marked
physical differences from the adjacent territories no great number of peculiar
forms can be expected, but there is nevertheless a small number of species and
sub-species which have not hitherto been recorded from anywhere else. One of
the most historically interesting of these probably peculiar species is Heliconian
hecale . This was figured by Cramer in 1774 under the name of Papilio pasifhoe
from “ Surinam ”, but no collector for more than a century has met with it
anywhere east of the Demerara River and as the Dutch Colony at the time
when Cramer’s work was published included the present counties of Berbice and
Demerara it not only seems probable that his specimens came from what we
now know to be its area of distribution, that is, the area between the Demerara
and Essequibo Rivers, but it gives rise to the interesting speculation as to
whether many of Cramer’s other Surinam species may not have come from
what is now British Guiana.

Amongst the different families of butterflies the Danmdae, amongst which
are now included the transparent and mimetic Tlhon^unae are in rather small
numbers (35 species), as is also the case oil the lower Amazon. The Nnhjndw
with 45 species^ are fairly well represented and the Brasnolalae although often
unnoticed on account of their crepuscular habits, have 15 species, a rather larger
number than in most of the adjacent countries. The seven species of Morpho is
a large number for such a small area, and these of course never escape the notice
of all those who visit the forests.

In the great family of Nj/nijdialtdar the Hilnonunae are the most olten
noticed owing to their bright colours and abundance in individuals but the
Acraetnae which are often so abundant in the Andean regions may almost be
said to be conspicuous by their absence, the only two species both being rare.
The true KynwhuUnne with 08 species are less abundant both in species and
individuals than is the case in the mountainous parts of the continent. The
Enjcimdae with nearly 190 species are as strongly represented as anywhere else
in the world, tniy family having its headquarters in Guiana and the lower
Amazon, but they are far from being such a prominent element in the fauna that
a mere catalogue would seem to suggest, many species being both rare and
inconspicuous.

The Papdiomdao have 27 species, the same number as is known from the
whole of the lower Amazon, but the Piendae with 29 species are more poorly
represented than in almost any other South American district of equal extent
although the number of ” whites ” and 44 yellows ” nearly always to be seen
along the banks of the rivers would give a contrary impression. The smaller
Lycaemdao and Henpendae have not yet been sufficiently collected to give any
just ifea of their numbers and it is in these two families and in the hnjcinidae
that the greatest number of additions to our list is to be expected. f

PLATE VIII.

pi K . | . — Xapeomtifs htp/ia Lodm. Female. *

Fig. 2 ,— C* rat* mn mnttUa cnnncra Mibsp. no\. remale (l,\pe).
Figl 3. -Psntthwtidn tr ana Hall. Male ( T\ pe).

Fig. 4 ,—ffcficonttis hrcit le clear* i Hall. Male.

F|g. 5. — Cataqramnui ttlas Mull. ^Female l nderside.

Fig. 6. -Pt/rrhoijttra xtratonicu* Frulist. Female.

Fig. 7.— Anna pitht/nxa mount i Hall. Female.

Fig. 8 . — Antirrlura tat/t/clina rotftcat/t Mibsp. mu bemale
Fig. g .—Dixmorphia crista roraimtv subsp. no\ (T>pe).

(All figures slightly reduced).

CATALOGUE OF tHt LBPIOOPTBBA RHOPALOCiRA OF BRITISH GUIANA. 2?

The records in the present Catalogue are taken chiefly from the following
collections, all of which have been carefully examined :

(i) The British Museum (Natural History). This includes the large
collections made by H. Whitely on the Mazaruni, at Annai on the Essequibo, at
Takutu, Quonga, and on the Carimang or Karana ng River (the former is the
Spelling on the labels and is therefore here adopted), and at other places on his
journey to Mount Roraima ; by W. Schaus at Omai and on the Essequibo ; by G.
Rodway and others on the Demerara River ; by H. Patoir on the Berbico and
many other specimens received from various collectors. With regard to these
British Museum localities it may be well to note that the species labelled “ Mt.
Roraima ” are practically all lowland forms and were evidently not collected at
any great elevation. We have not been able to locate Quonga which was
presumably some now abandoned settlement near the Upper Mazaruni or its
tributary the Carimang River.

(ii) The Georgetown Museum. This contains a fairly representative
collection of the butterflies of the country ; unfortunately the specimens have no
exact locality labels but the majority are said to have come from the Demerara
River.

(iii) Collections made by W. J. Kaye and his collector H. Roberts, chiefly
at Tumatumari and on the old Potaro Road.

(iv) Specimens collected by myself at Parika at the moulli of the Esse-
quibo and at Bartica and Mabaruma (N. W. District) in December 1 920 and
January 1930 and again at Parika, Bartica and the Kaieteur Falls in February
and March 1930.

(v) The collection of the Entomological Division of the Department of
Agriculture, British Guiana.

A small but very interesting collection made by G. A. Hudson on the Upper
Kutari River and Upper Corentyne near the Brazil-Kurinam frontier has quite
recently come to the British Museum and still later a few specimens obtained
by Major Beddington near the Oronoque-New River confluence in the same
region, but with these exceptions records from the eastern part of the Colony,
the Rupununi Savannahs and the mountains of the S. W. frontier are very scant
and more information about the species found there would be very welcome.

Lastly, I have come across a paper by Dr. Roger Verity of Florence in the
Mem. Soc. Ent, Italiana for 1934 on the butterflies collected by the Beccari
Expedition and several species only recorded from this source are here included
in the addenda.

I have particularly to thank Messrs. N. D. Riley of the British Museum
(Natural History), L. D. Cleare of the Department of Agriculture, Georgetown,
and W. J. Kaye, F.R.E.S., for their assistance in compiling the present Cata-
logue. A special debt of gratitude is also due to Professor J. S. Dash, Director
of Agriculture, for kindly consenting to publish it in The Af/nculhnril Journal.

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

£x, i.

Family DANAIDAE.

Sub-family DANAINAE.

1. Danais archippus.

Papilio archippus , Fab., Ent. Syst., Ill, (i), p.49 (1793).

Generally common. Larva conspicuous on Asclepias.

2. Danais eresimus.

Papilio eresimus , Cramer, Pap. Exot. II, t. 175, G.H. (1779).
Annai. Apparently scarce and local.

3. LYCOREA PAS1NUNTIA.

Papilio pasinantia , Cram., Pap. Exot. IV, t. 310, A. — C. (1782).
Omai ; Annai ; Mabaruma ; Potaro Road. Sometimes common.

4. LYCOREA CERES.

Papilio ceres , Cram., Pap. Exot. I, t. 90 A. (1779).

Annai ; Quonga ; Mabaruma ; Potaro Road. Locally common and very
variable. The tendency for the marginal and median bands of the hind wings
to unite so as to form a broad black outer patch is characteristic of the Guiana
forms of the mimetic group of which this species is probably the primary model,
the other members of the association being Ilirsufis harmonia , Melinaea
mneme, M. crameri , Meehan it i s polt/mnia , J/. pannifera , the three species of
Ceratinia and Heliconius numata .

Sub-family— ITHOMIINAE.

5. Thyridia confusa.

Methona confusa , Butler, Cist. Ent. I, p. 151 (1873).

Annai ; Potaro River ; Kuturi River (G. A. Hudson),

6. HlRStJTIS HARMONIA.

Papilio harmonia , Cramer, Pap. Exot. II, t. 190, D (1779).

Annai ; Kuturi River. Always scarce and local.

7. Melinaea mneme.

Papilio mneme , Linnaeus, Syst. Nat. I, (2), p. 756 (1767).

Generally common in forests.

8. Melinaea mediatrix.

M, mediatrix, Weymer, Stett. Ent. Zeit. LI, p. 282.

Common with the foregoing and sometimes even more abundant. A
frequent aberration is mauensis Weym. in which the hind wings have two
separate bands.

9. Melinaea mnasias tecta.

ilf. mnasias tecta , Haensch in Seitz, Gross-Schmetterlinge V, p. 124
* (1909).

Described from British Guiana. Mr. W. J. Kaye has a specimen from the
Potaro Road.

CATALOGUE OF THE tKPJDOPTERA RHOPALOCERA OF BRITISH GUIANA. 20

10. Melinaea KGINA.

Papilio pghniy Cramer, Pap. Exot. II, t. 191 D (1779).

Annai ; Omai ; Carimang River ; Potaro River ; Uppor Corentyne.

11. Mechanitis polymnia.

Papilio polymnia , Linn., Mus. Ulr. p. 224 (1704).

Abundant in most wooded places.

12. Mechanitis pannifera.

M . pannifora , Butler, Cist. Ent. II, p. 150

Rather more local than M. polymnia but often abundant. Annai ; Omai ;
Takutu ; Mabaruma ; Kaieteur Falls.

13. Aprotopos psidii.

Papilio pnidii Linn., Mus. Ulr. p. 228 (17G4)

Potaro River (W. J. Kaye); Kuturi River (G. A. Hudson).

14. Callithomia aijexirrhoe.

(7. alcxirrhor , Bates, Trans. Linn. Hoc. XXIII, p. 522 (1862).

A series labelled “ British Guiana, Parish” in the British Museum.

15. Ceratinia mutilla

Tihomnt maliUa y Hewitson, Ex. Butt. IV, Ithomia t. 25 f. 153 (1867).
Domerara River ; Carimang River ; Bartica ; Mabaruma. In the British
Museum there are three pairs from Mt. Roraima which represent a local race
having the two black bands of the hind wings completely fused together so as to
form a single patch. I propose to call this form connoxa form. nov. (Plate VIII,
Fig. 2, female).

16. Ceratinia pellucida.

(7. pcllacida , Haensch, Berl. Ent. Zeit, L, p. 154.

Common at the Kaieteur Falls. In the British Museum from Annai and a
slightly different form from Omai.

17. Ceratinia barh.

C. bard , Bates, Trans. Linn. Hoc. XXIII, p. 524 (1862).

Demerara River ; Omai ; Quonga ; Annai ; Takutu ; Mt. Roraima.

18. Ceratinia glycon.

Napcogrnes yhyron , Godman, Ann. Mag. Nat. Hist. 1889, (3), p. 157.
Annai ; Carimang River ; Takutu ; Potaro River ; Kaieteur Falls, Common
where found.

19. Napeogenes oyrianassa.

Sais n/rianami , Doubleday A Hewitson, Gen. Diurn. Lep. t. 18. f. 1
(1847).

Represented iu British Guiana by two forms, adalta Haensch and diluluta
Haensch ; the former is in the 1 British Museum from Bartica, the Carimang
River and Esseiiuibo ; the latter from ” British Guiana”

20. Napeogenes HYGIA. ^Plate VIII, Fig. 1, female).

N. hygia , Godman, Ann, Mag. Nat. Hist. 1899, (3), p. 157.

A single specimen was taken on the Upper Kuturi River by G. A. Hudson ;
the only oxanfple previously known was the type from Paramaribo.

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

tx, 1.

21. Napeogenes potaronus.

N. jvtaronus, Kaye, Ent. Rec. XVII, p. 120.

Poiaro River (W. J. Kaye) ; Kaieteur Falls (A. Hall.) Very rare.

22. Napeogenes inachia moles.

N. moh'8, Haensch, Berl. Eat. Zeit. L, p. 157, t. 4, f. 10 (1905).

Potaro Road ; also in the British Mnseum from “ British Guiana.”

23. Sais ROSALIA.

Papilic romhdy Cramer, Pap. Ex. Ill, t. 246, B. (1782).

Omai ; Demerara River ; Berbice ; Kuturi River.

24. Sais paraensis camariensis.

*V. ('((niarirnfii.% Haensch, Berl. Ent. Zeit. L, p. 162, t. 4, f. 12 (1905).
Described from Camaria on the Cuyuni. There are specimens in the
British Museum labelled “ Georgetown”.

25. Scad a theaphia.

Oleria theaphia , Bates, Trans. Linn. Soc. XXIII, p. 529 (1862\

Annai; Quonga; Carimang River; Potaro Road; Kaioteur Falls. Specimens
from the Potaro Road were described as majascuta Haensch, but I am unable
to see that they .differ from the typical form.

26. Dircenna lenea.

Papilla Jenra, Cramer, Pap. Ex. ID, t. 231, I). (1782).

Omai; Annai ; Takutu ; Mabaruma ; Mt. Roraima; Kuturi River. At
Mabaruma I took typical specimens in company with a very pale form
which has been described as dnxjheda Weeks.

27. Calloleria nise.

Papiho ntxe, Cramer, Pap. Ex. Ill, t. 231, E. (1782).

Annai ; Oinxi ; Ciriming River ; Demerara River ; Mabaruma. Locally
abundant.

28. Calloleria cayan\.

(\ cntjcum, Salvin, Ann. Mag. Nat. Hist. (4), IV, p. 167.

Potaro River ; Kaieteur Falls. Rare.

29. Episcada sylph \.

E. Hj/lphdy Haensch, Berl. Ent. Zeit. L, p. 171 (1905).

A single specimen from Quonga in the British Museum differs somewhat
from typical Venezuelan examples and may represent a new iace.

30. Leucothyris aeolk.

Papiho aetjlr, Fabricius, Gen. Ins. p. 255 (1777).

Bartica ; Carimang River ; Potaro River ; Kaieteur Falls.

31. LljUCOTHYRIS ZAltEPHA.

* Tthomia zarrpha , Hewitson, Ex. Bull. IV, Ithomia t. 27, t. 173 (1869).
Demerara River ; Essequi bo River ; Carimang River; Bartica; Kaieteur Falls.

CATALOGUE OF THE LBPIDOPTERA RHOPALOCERA OF BELTIKH GUIANA. 31

32. Leucothyrih astrea.

Pupilio Mirra* Cramer, Pap. Ex. I, t. 22, D. (1775).

Annai ; Carimang River ; Quonga ; Mabaruma. Generally found singly
and therefore rare.

33. Aeria eurimedia.

Pupilio eurimrdia , Cramer, Pap. Ex. II, t. 126, C.D. (1779),

Carimang River; Takutu; Kaieteur Falls; Lower Essequibo River; Mabaruma.

34. PSEUDOSCADA FLORULA EXORNATA.

P. flora la ab e.roniata, Haenscb, Berl. Ent. Zeit. L, p. 177 (1905),
Potaro Road. A rare species.

35. PSEUDOSCADA wana. (Plate VIII, Fig. 3 male).

P . tvtiau* Hall, “Entomologist” 1930, p. 278.

Only known from Mabaruma where I took the types in December 1929.

Family SATYR IDAE.

36. Callttaera philis.

Pupilio phi! is* Cramer, Pap. Ex. IV, t. 387, K. (1782).

Domerara River ; Bartica ; Carimang River ; Mt. Roraiirm. A l’are and
beautiful species, always found singly.

37. IIaktera piera.

Pupilio pirra , Linnaeus, Mus. Fir. p. 220 (1764).

Demerara River ; Bartica ; Parika ; Carimang River ; Mabaruma ; Kaieteur
Falls. Not rare in heavy forest.

38. PlERELLA ASTYOCHE.

Ilrtarra astyoche, Erichson, Schomb. Reisen III, p. 599 (1848).
Mabaruma ; Carimang River ; Lower Essequibo River.

39. PlERELLA LENA.

Pupilio Iran, Linnaeus, Syst. Nat. I, (2), p. 784 (1767).

Demerara River ; Bartica ; Carimang River ; Mt. Roraima. Not very com-
mon anywhere.

40. PlERELLA DRACONTIS,

Pirns ( lracontis , Hiibner, Verz. Bek. Schmett. p. 53, n. 500 (1816).
Common in most wooded places.

41. PlERELLA LAMIA.

Pupilio lamia, Sulzer, Gesch. Ins. t. 18, f. 1. (1776)

Demerara River; Berbice ; Omai; Carimang River; Kaieteur Falls; Mt.
Roraima. Common where found.

42. Antirrhaea philoctetes.

Pupilio philoctetes , Linnaeus, Mus. Ulr. p. 219 (1764).

Demerara River ; Berbice ; Bartica ; Parika ; Mt. Roraima. Rather scarce
and difficult to oatch owing to its habit of flying close to the ground in the
dense undergrowth.

AGRICULTURAL JOURNAL OF BRITISH GUIANA

[X, X.

43. Antirrhaea ornata.

A. ornata , Butler, Ann. Mag. Nat. Hist. (4) V. p. 3G2.

A single specimen from Quonga in the British Museum.

44. Antirrhaea taygetina rodwayi. (Plate VIII, Fig. 8 female).

A. taygetina rodwayi , eubsp. nov.

Description. — Differs from typical A, taygdina Bull, in both sexes having
the postdiscal spots of the hind wings very large and bright blue, 4 to 7
millimetres in diameter and in the rufous scaling on the outer part of the fore-
wings being less pronounced.

Described from two pairs from Anna! and two pairs from “British
Guiana,” all in the British Museum.

45. Caerois ohorinarus.

Papiho cftonnaems, Fabricius, Syst. Ent. p. 484, n. 182 (1775).

I have taken this fine species at Parika and it is reported from the Demerara
River, but it seems to be very rare.

4f>. Taygetis mermeria.

Papilio menneria, Cramer, Pap Ex. I, t. t)C>, B. (1770).

A series from Takutu in the British Museum.

47. Taygetis TjARUa.

T. lama , Felder, Reise Nov. Lep. Ill, p, 1(50, n. 700 (18(57).

Takutu; Mt. Roraima. Not a common species.

18. Taygetis virgtija.

Papilio virgilia , Cramer, Pap. Ex. I, t. 0(5, C. (1770).

Not uncommon in shady places,

40. Taygetib celi a.

Papiho vet id , Cramer, Pap. Ex. Ill, t. 212, C. (1782).

There are single specimens from Demerara and Mt. Roraima in tne British
Museum.

50. TAYGETTS ANDROMEDA.

Papilla andromeda , Cramer, Pap. Ex. I, t. Of), A. (1770).

The commonest species of the genus and, like its allies, fond of the
shady paths in the forest.

51. Taygetis xenana.

7\ xenana, Butler, Lep. Ex. I, t. 7, f. 3 (1870).

Annai ; Bartica ; Kaieteur Falls. This very dusky species is easily
overlooked on account of its resemblance to T. andromeda .

52. Taygetis echo.

rapilio echo, Cramer, Pap. Ex. I, t. 57, C.D. (1770;.

Demerara River ; Annai ; Takutu.

53. Taygetis penelea.

^ Papilio penelea , Cramer, Pap. Ex. II, t. 101, G. (1770).

The only specimens I have seen are merely labelled “ British Guiana,” It
is a very common species in Trinidad. *

CATALOGUE OP THE LEPIDOPTERA RHOPALOOERA OK BRITISH liUlANA. 33

54. TAYGETIH VALENTINA.

Papilio Valentina, Cramer, Pap. Ex. Ill, t. 242, A, (1782).

Four males from Berbice in the British Museum. It is one of the rarer
species.

55. Euptychta hesione.

Papilio hesione , Sulzer, Geoch. Ins. p. 144, t. 17, f. 3, 4 (1770).
Generally distributed and very common.

50. Euptyohia bixocula.

E. binocula, Butler, Lep. Ex. I, t. 4, f. 5 (1869).

Found in company with the foregoing but much more local. Bartiea t
Parika ; Quonga ; Carimang River.

57. Euptychta ocypete.

Papilio oei/pete, Fabricius, Gen. Ins. p. 260, (1777).

Omai ; Annai.

58. Euptyohia lydia.

Papilio hjdia, Cramer, Pap. Ex. II, t. 148, C.D. (1779).

Demerara River ; Annai ; Carimang River ; Kaieteur Falls ; Mt. Roraima ;
Parika. This species is not very abundant anywhere.

59. Euptyohia picea.

E, picea , Butler, Proc. Zool. Soc. 1866, p. 481. t. 12, f. 0 (1807 )
Demerara River ; Carimang River ; Bartiea ; Kaieteur Falls. At the latter
locality I took a remarkable aberration in which the red stripes appear on the
upperside.

60. Euptychi \ myxcea.

Papilio nnjncea, Cramer, Pap. Ex. IY, t. 293, C. (1782).

Very common and generally distributed.

61. Euptyohia pexelope.

Papilio penelope. Fabricius, Syst. Ent. p. 493, n. 217 (1775).

Another very common species, perhaps more abundant than the preceding.

62. Euptyohia tkrrestris.

E. fewest ris, Butler, Proc. Zool. Soc. 1866, p. 462, t. 39 f. 1.

Widely distributed but less abundant than the two foregoing.

63. Euptyohia batesii.

E. batesii, Butler, Proc. Zool. Soc. 1866, p. 493, t. 40, f. 16.
Demerara River; Carimang River ; Omai ; Kaieteur Falls. A rare species
only found singly.

64. EUPT'YCHIA RENATA.

Papilio renata, Cramer, Pap. Ex. IV. t. 326, A. (1782).

Common in many localities. Demerara River ; Omai ; Parika; Carimang River.

65. Euptyohia modesta.

E. modesta, Butler, Proc. Zool. Soc. 1866, p. 472, n. 42.

Parika; Bartiea; Carimang River; Not rare but easily overlooked on account
of its resembftmee to E. renata .

34 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 1.

6G. EUPTTCHIA HERMES.

Pajiilio hermes , Fabricius, Syst. Ent. p. 487, n. 195 (1775).

Probably the commonest butterfly throughout Tropical America.
Abundant everywhere and at all seasons.

07. Euptychia argantb.

Pajiilio argante, Cramer, Pap. Ex. Ill, t. 201, C.D. (1782).

In the British Museum from Demerara.

08. Euptychia liryb.

Pajiilio lilnjr, Linnaeus, Syst. Nat. I, (2). p. 772, n. 146 (1767).
Common in forests and undergrowth.

09. Euptychia gulnare.

K. guliHiiv, Butler, Ent. Mo. Mag. VI, ]>. 250 t. 1, f. 3 (1870).

A male from “ British Guiana” in the British Museum.

70. Euptychia erictho.

K. erictho, Butler, Proc. Zool. Soc. 1800, p. 501, t. 40, f. 12.

Oarimang River : Kaieteur Falls ; Mt. Roraima. Common where it occurs.

71. Euptychia tricolor.

K. tricolor, Ilewitson, Ann. Mag. Nat. Hist. (2), VI, p. 440 (1840).
There is a specimen of this rare and beautiful species from the Potaro
River (H. Roberts) in the collection of W. J. Kaye and one from Demerara in
the British Museum. Oronoque-New River Confluence (G. A. Hudson). R.
Snpenaam (coll. Ent. Div. G. Brinsley).

72. EUPTYCHTA I.EA.

Pajiilio lea, Cramer, Pap. Ex. II, t. 151, C.D. (1779).

Berbice: Annai.

73. Euptychia cephus.

Pajiilio ce/j/nift, Fabricius, Syst. Ent. p. 528, n. 359 (1779).

In the Georgetown Museum and in the British Museum from Demerara.
Fond of dense undergrowth.

74. Euptychia arnaea.

Pajiilio droned, Fabricius, Gen. Ins. p. 200 (1777).

A common species in forests.

75. Euptychia chlorik.

Pajiilio chlorhf, Cramer, Pap. Ex. IV, t. 293, A. B. (1782).

Bartica: Annai; Carimang River. This species and the next arc generally
found together but are never common.

70. Euptychta herhe.

Pajiilio herse, Cramer, Pap. Ex. I, t. 10, C.D. (1775).

Bartica ; Carimang River ; Annai ; Omai.

77. SPPTYCHIA TOLUMN1A.

Pajiilio tot amnia, Cramer, Pap. Ex. II, t. 130. F.G. (1779).

Single specimens from Berbice and “ British Guiana,” in the British
Museum. -

CATALOGUE OB THE LEBlDOPTBRA RHOPALOCERA OP BRITISH GUIANA. 35

78. Euptychia hewitsonii.

E. Hewitsonii , Butler, Proc. Zool. Soc. 18C6, p. 491. t. 40, f. 4.

Bartica ; Annai ; Oarimang River ; Quonga. This curious little species is
always found singly.

79. Euptychia cluena,

Papilio cluena , Drury, 111. Ex. Ent. Ill, t. 7, f. 5, G (1782).

A pair from Mt. lloraimi in the British Museum.

80. Bia aotorjon.

Papilio aclorion , Linnaeus, Syst. Nat. I, (2), p. 794, n. 262, (1767).
Generally distributed in dense undergrowth.

Family BRASSOL1DAE.

81. Brassolis sophorak.

Papilio sophorar , Linnaeus, Syst. Nat. X, p. 471, n. 83 (1758).
Common round Georgetown and in most of the coastal districts. The larva
feeds upon Cabbage Palm and Coconut, clusters of the pupae often being found
in the spathes. The larvae are much infested by dipterous parasites and when
they escape these, the freshly emerged butterflies ofteu fall to the ground before
the wings are fully expanded and so fall victims to ants.

82. I)YN T \STOR DARIUS.

Pa pi l to ( lariax , Fabricius, Syst. Ent. p. 482, n. 173 (1775).

A specimen flew into the rest house at Mabaruma during my stay theie but
evaded capture.

83. OPSIPHANES CASSIAE.

Papilio ctmiw\ Linnaeus, Mas. Fir. p. 2G5 (17G4).

A single specimen from Deiuerara in the British Museum.

Si. OPSIPHANES QUITEUIA.

Papilio (jo Herat, Cramer, Pap. Ex. IV, t. 313, A — I). (1782).

In the British Museum from Mt. Roraima.

85. OPSIPHANES IXYlltAE.

rofttmis saperha invirtte , lliibner, Sam ml. Ex. Schmett. t, 76, f. 1, 2
(1806-16).

Demerara : Berbiee ; Mt. Roraima. Probably common in most forest
regions.

86. Opsiphanes cassixa meriaxae.

0 . cassina merianae , Stichel, Berl. Ent. Zeit. XLVI. p. 518 (1901).
Two females from Demerara in the British Museum.

87. Catoblepia xanthus.

Papilio xanthus, Linnaeus, Mus. Fir. p. 276 (1764).

Demerara River : Bartica. Rare.

88. Catoblepia berecynthia.

Papilio berecynthia , Cramer, Pap. Ex. II, t. 181, B.C. (1779).

Parika ; Bartica ; Carimang River ; Mt* Roraima.

36 AGRICULTURAL JOURNAL OF BRITISH GUIANA. DC, 1.

89. Eryphanis polyxena.

PapiUo polyxcna % Meerburg, Afb. Zeldz. Gen. t. 41 (1775).

Demerara River ; Takutu ; Mt. Roraima.

90. Caligo teucer.

PapiUo teucer , Linnaeus, Mas. Ulr. p. 212 (1764).

Not uncommon in many places, usually at the edges of cocoa plantations.
Parika ; Demerara River ; Berbice.

91. Caligo ilioneus.

PapiUo iiioneus , Cramer, Pap. Ex. I, t. 52, A. (1779).

The commonest species of the genus and very generally distributed, the
larva feeding upon sugar cane.

92. Caligo eurilochits.

PapiUo cnrilochus , Cramer, Pap. Ex. I, t. 33, A., A. 34, A. (1775).
Demerara River ; Friendship on the Berbice ; Takutu.

93. Caligo idomeneus.

PapiUo idoinenrus, Linnaeus, Mils. Fir. p. 2J3 (1764).

Demerara River ; Berbice ; Curimang River ; Kaieteur Falls.

94. Caligo o'ileus.

Pavonia oiteus , Felder, Wien. Ent. Mon. V, p. 1 11, n. 1 0C» (186l).
Marudi Mts., Rupununi District, (L.H.J. Ashburner).

95. Caligo suz vnna,

Paroaia s atatnta, Deyrolle, Rev. Zool. 1872, p. 275, JI. 24, 26.

There are specimens of this rare species in the Georgetown Museum and
one from “British Guiana” in the British Museum. Demerara (Verity).

Family MOKPIIIDAE.

96. Morpho PERSEUS.

PapiUo persons, Cramer, Pap. Ex. 1, t. 71, A.B. (1779).

(a). PapiUo mrte/lus . Cramer, Pap. Ex. Ill, 218, A.B. (1782).

This fine species occurs in two forms both of which are equally scarce. In
metellus the colour above is golden yellow whilst in prrseto ? it is light blue.
There are specimens of both forms in the Georgetown Museum and in the British
Museum from Demerara, and tlio latter institution also has an intermediate
specimen from the same district. Mackenzie (Verity).

97. Morpho hecuha.

PapiUo h&'ubn, Linnaeus, Mant. Plant, p. 531 (1771).

This is the largest of all South American butterflies and owing to its lofty
flight it is very rarely captured. I have seen the species filing high above the
tree** tops at the foot of the Kaieteur Falls and along the Potato Road and there
are specimens in the Georgetown Museum and in the British Museum from
Demerara. Mackenzie (Verity).

CATALOGUE OF THE LEPIDOPTERA RHOPALOCERA OF BRITISH GUIANA. 37

98. Morpho achtlles.

Papilio ar/tille.% Linnaeus, Mus. TTlr. p. 211 (17G4).

The commonest species of the genus. It is found in most wooded places
and as its flight is lower anil slower than most of the other species it is the one
most often noticed. It is fond of settling on decaying fruits on the ground and
will also come to sugar.

99. Morpho deidami a.

L/onle drain mat, Hiibner, Verz. Bek. Schmett. p. 52, n. 187 (181G).
Several at Mabaruma (A. Hall).

100. Morpho adonis.

Papilio (/don is, Cramer, Pap. Ex. I. t. Gl, A.B. (1779).

Mr. W. J. Kaye has S])i*cimenK from the Potaro River.

101. Morpho rhetenor.

Pap/ ho rladrnor, Cramer, Pap. Ex. I. t. 15, A.B. (1775).

The most brilliant of all species on the wing. It occurs rarely on the
Demerara River and I saw one specimen at the foot of the Kaieteur Falls in
March.

102. Morpho mkxelws.

Paptho menelaa*, Linnaeus, Mus. TTlr. p. 200 0704).

Next to M. wli/lh**, this is the most widely distributed species of the genus
and is often common where it occurs, as at Birtica, Mabaruma. on the Potaro
Road and elsewhere.

Family NYMPH ALT DAK.

Sub-family— ACRAEINAE.

103. ACTTNOTE THVLTA.

Ptf/nho thaha, Linnaeus, Mus. Vlr. p 2o0(17G4).

Demerara River ; Berbice ; Takutu. Apparently not very common where
it is found.

104. Actinoth ante vs.

Amaru antra*, Doubleday & Hewitson, Gen. Diurn. Lep. t, 18, f. 5
(1848).

A. antra* f. oehrotaeniata , Jordan, in Seitz, Gross.-Schmett. Y, p.
3(59 (1913).

There are two pairs of the dimorphic form o/hrotaen/ata from Mt. Roraima
in the British Museum.

• Hub-family— HELICONIINEA.

Before dealing with the forms oi this interesting group it is necessary to
remark that many species of Helicon i a#, particularly H . melpomrne, H. dor is
and //. erato are highly polymorphic and have developc d a number of forms
which have at first sight all the aspect of different species, whilst in other cases
the influence of mimicry has produced forms of different species which have a
great similarity to ono another and are sometimes difficult to distinguish.

AGRICULTURAL JOURNAL OF BRITISH GUIANA*

[X, 1.

Mach has been written on this subject by Messrs. Charles Oberthiir, W. J.
Kaye, H. Eltringham, H. Riffarth, A Seitz and others but unfortunately no
two authors are quite in agreement in their conclusions. In British Guiarta the
species are far more constant than is the case in Surinam or French Guiana but
there are nevertheless a number of interesting varieties whose exact relationship
can only be eventually proved by breeding. I therefore express no opinion as
to how far the forms hero recorded are specifically distinct.

105. Heltconius numata.

Papilio numata, Cramer, Pap. Ex. IV, t, 297, C.D. (1782).

A common species in most inland districts but apparently not found close to
the sea. Lower Essequibo River (Bartioa-Suponaam Forest Survey. In Coll. Ent.
Div.) Ah. mrlanops Weymer is a common form in which the two black bands
of the hind wings are confluent. Other aberrations have been named guiensis
Riffarth and mavors Weymer.

106. Heltconttts grapattjs thtet/rt.

H. gradatus thieJri, Riffarth, Berl. Ent. Zeit. XLV, p. 111.") (1900).

Several specimens from Berbice and Deinerara a,nd two taken by myself at

Bartica have been placed under this name in the British Museum. It looks very

much like a further aberration of numata .

107. Heijcontus euooma.

Eurides rucoma, Hiibner, Zubr. Ex. Schmett. f.f>77, 578 (182.")).

A single specimen is recorded by W. .f. Kaye from the Potaro Road.

108. Hemcontus vetcstus.

II. vrtustus, Butler, Cist. Ent. I, p. 163, (1873).

Remerara River ; Bartica ; Berbice ; Potaro Road ; Mabaruma. Apparently
always rare.

109. HEUCONIUS 8TLVANA.

Papi/io silvana, Cramer, Pap. Ex. IV, t. 361, C.R. (1782).

Remerara River ; Annai ; Potaro Road ; Kuturi River ; Rare and only
fonnd singly,

110. HEUCONIUS ETHILLA SULPHURETT8.

H. sulphurous , Weymer, “ Iris ” VI, p. 311, t. 4. f.8 (1893).

A specimen from the Barima River in the collection of W. J. Kaye.

111. HELTOONirS HECALK.

Papilio hecalr, Fabricins, Gen. Ins. p. 254 (1777).

(a) H. hrcalr c/rarri. Hall, “ Entomologist ” LX II I, p.278 (1930).

This is one of the most striking of the butterflies which arc pecnliar to
British Gniana and is interesting as occurring in two distinct races. Typical
hecale is locally common near Parika and there are old specimens in the British
Museum labelled “ Remerara”. The form clearei is only known from a restricted
spot *at Mabarnma where I discovered it in December 1929. A remarkable
aberration called Julvoscrns, Lathy, is said to have come from Deinerara but only
the type specimen is known. *

CATALOGUE OP THE LEPIDOFTEBA RHOPALOCEBA OP BRITISH GUIANA. 39

112. Helicontuh tumatttmart.

H. tumatumari, Kaye, “ Entomologist,” 1906, p. 53.

Only known from Tumatnmari where it was discovered by W. J. Kaye.

113. He r. room us melpomenh.

Papilio molpomme , Linnaeus, Mns. Ulr. p. 232 (1764).

The typical form is generally distributed and rather common. From
Parika I have specimens of ah. ntroseda Riffarth in which the red band is partly
broken up into spots and from Mt. Roraima the British Museum has four males
and a female of a totally different form near to the one figured in Seitz as eu/alia
Riff, but with the yellow spots of the fore-wings larger, the males with an
additional small spot between them.

114. Heltooniuk aede astydamia.

11. aulydaima, Erichson, Schomb. Reisen III, p. 595 (1848).

Demerara River ; Bartica ; Annai : Quonga; Potaro Road ; Takutu. Only
found singly.

115. Helioonius xanthoolek.

H. .raiithoclri, Bates, Trans. Linn. Soc. XXIII, p 561 (1862)

Demerara River ; Omai ; Quonga ; Potaro Road. Like the preceding
species it is always rare.

116. HeLIOONIUK BURNEYT HUBNER1.

H. buryncyt hurbnen, Standinger, ‘'Iris’’ IX, p. 312 (1896).

Demerara River ; Omai ; Annai ; Takutu ; Bartica ; Mt. Itoraima.

117. IlELlCONIUS EGERIA.

Papilio eyo ia, Cramer, Pap. Ex. 1. 1. 34, B.C. f 1775).

A single specimen received by W. .1. Kaye from the Totaro Road. It is
always a rare species.

118. Heuconics DORIS.

Papiho <lori«, Linnaeus, Mant. Plant, p. 536 (1771).

Generally distributed but rarely common at any one place. This species is
polymorphic but only two forms seem to be at present known from British
Guiana, namely typical dor id in which the hind wings have a blue band and
ah. dclila Hubn. with broad red Btreaks on the hind wings. Both forms occur
together at Annai, Berbice and Mabaruma.

119. IlELlCONirS CLYTIA FLAVHSCENS.

H. clytia Jlavedcem, Weymer, Stett. Ent. Zeit. LI, p. 292.

Parika ; Bartica ; Annai ; Mabaruma. Typical II. chjiia with white bands
does not seem to occur in British Guiana.

120. IlEHCONirS WALLACEl.

H. irallacd, Reakirt, Proc. Ac. Nat. Sc. Phil. 1866, p. 242.

Annai ; Mabaruma. Closely related to II. clytia and perhaps only another
form of it.

121. Heliconius anttochus.

Papilio antiochus, Linnaeus, Syst, Nat. I, (2), Add. p. 1068 (1 767).
Demerara River ; Omai ; Quonga : Bartica ; Kamakusa. Often very
abundant but Uncertain in appearance.

AC? RICULTUR A L JOURNAL OF BRITISH GUIANA.

LX, i.

122, Hblioonius sara rhea.

Papilio rhea 9 Cramer, Pap, Ex. I, t. 54, O.D. (1775).

Oae of the most generally distributed species and often abundant. A form
called ab. brevinnculata Stgr. with the band of the fore-wings broken into two
spots is found at Mabaruma and probably also elsewhere.

12I5. Heliconius hydara vtcttlata.

11. hydara vicuJata , Riffarth, Berl. Ent. Zeit. XLV, p.188 (1905).

The commonest of the red-banded species of Hr! icon ins, especially in
districts near the coast. Ab. dryope Riff, with a red stripe at the base of fore-
wings and ab, coral ii Butl. with the red ban l broken into spots are known to us
from Annai.

124. Heliconius erato magntfioa.

Z7. wrlpomene maynifica , Riffarth, Berl. Ent. Zeit. XLV, p.211, (1005).
Abundant in many inland districts such as Mabaruma and the Kaieteur Falls
where it seems largely to replace I'iculata. The form earyas Riffarth from the
Oarimang River, Annai and Berbice hardly seems to differ.

125. Eueides rtcini.

Papilio ncini, Linnaeus, Mus. Dir. p. 227, (17(54).

Annai. According to Kaye the larva feeds upon ' Cassava as well as on
Passifiora.

12(5. Eueides tAles.

Papilio talri, Cramer, Pap. Ex. I. t. 58, O.D. (177(5.)

Occurs rarely at Bartica and on the Demorara River.

127. EUETDES IjAMPETO NTGROFULVA.

E. ntyrofufra , Kaye, “ Entomologist ” 190(5, p 52.

Discovered by C, B. Roberts on the Potaro River where it seems to be not
uncommon locally.

128. Eueides vibtlia,

Cethosia vibilia, Godart, Enc. Meth, IX, p. 215, n.CJ (1819),

Potaro Road. Rare.

129. EUETDES ISABELLA

Papilio Isabella , Cramer, Pap. Ex, IV, t. 350, O.D. (1 782).

Berbice ; Annai ; Potaro Road. Apparently less common than in other
parts of South America.

130. Eueides lybia.

Papilio lybia , Fabricius, Syst. Ent. p. 400, n. 75 (1775).

Generally distributed in wooded districts and often common.

131. Euetdes aliphera,

Cethosia aliphera , Godart, Enc. Meth, IX. p. 240, n, 7 (1919).

Very common in almost all localities.

Sub-family— NYMPHALINAE.

132. Metamorpha dido.

4 Papilio dido , Linnaeus, Syst. Nat, I, p. 782 (1758).

A fairly common species, sometimes to be seen even in the streets of
Georgetown. * The larva feeds upon Passifiora, not Pineapple as stated by
Madam Meiiam. 9

CATALOGUE OP THE LBPIDOPTERA RHOPALOCERA OP BRITISH GUIANA. 41

133. COLAENIS JULIA.

Papilio julia, Fabricius, SyBt. Ent. p. 509, n. 281 (1775).

Generally distributed and common.

134. COLAENIS rHAETUSA.

Pupil io phaetusa, Linnaeus, Syst, Nat. I, p. 486, n. 123 (1758).

Locally common, chiefly in swampy districts near the coast. Not rare in the
Botanical Gardens and other spots near Georgetown.

135. Dion is vanillae.

Papilio vanillae , Linnaeus, Syst Nat 1, p. 482, n. 146 (1758).

Generally distributed and common.

136. Dione JUNO.

Papilio jam, Cramer, Pap. Ex. Ill, t. 215, B.C. (1782).

Generally distributed but not so abundant as I). vanillae. The larva
likewise lives upon Passifiora.

137. Epptoieta hkgesia.

Papilio heyrsia, Cramer, Pap. Ex- HI, t. 209, E.F, (1782).

In the British Museum from Demerara. Apparently rarer than in most
parts of South America.

138. PHYTIOI)S> liimope.

Papilio I i nope, Cramer, Pap. Ex. I, t.l, C.D, (17/5).

Generally distributed and often abundant chiefly in the wet seasons. The
small pale form tlu/iartus Fabr. which occurs at Mabaruma and elsewhere is
sometimes regarded as a different species.

139. PllVt'IODES EONTUS.

P. font as, Hall, "Entomologist” LXI, p. 11 (1928).

The typo specimen, labelled “ British Guiana” is the only one at present
known. This crm a from the collection of II. Grose Smith who received most
of his material from the Essequibo district.

140. PHYCIODES CLIO.

Papilio dm, Linnaeus, Syst. Nat. I. p. 167, n.52 (1758).

Generally distributed and sometimes abundant in or near forests.

141. Phyciodes nyuplia.

Papilio nanplia, Linnaeus, Syst. Nat. I, p.448 (1758).

Demerara Iliver ; Berbice ; Kuturi liiver.

142 Phyciodes kuniok.

Nereis fu/va aunice, Hiibner, Samml. Ex. Schmett. t. 9. f.l-i (1806 — 18).
Generally distributed in forests lmt usually only found singly. Bather
common near the top of the lvaieteur Falls in March 1936.

143- Phyciodes aveyrona.

Eresia aveyrona, Bates, Journ. Ent. II, p. 192 1. 10, f.4 (1861).

A sing'le specimen in my collection from the Barima River.

144, CHLOSYNE IAC1WA SAUNDEKSI1.

Syndilor Saandcrsii , Donbleday A Ilewitson, Gen. Diurn. Lep. t. 24,
f.2 (1847).

A specimen in the British Museum labelled “British Guiana, Parish.” It
is a very common species in Venezuela and in Trinidad.

(To be continued)

NEWS.

Professor J. Sydney Dash, Director of Agriculture, left the Colony for Bar-
bados on two weeks’ leave of absence on December 24, 1938, returning on
January 5, 1939. During Professor Dash’s absence Mr. L. D. Cloare, Entomolo-
gist, was appointed to act as Director and subsequently as Deputy Director.

Mr. C. LI. B. Williams, Sugar Agronomist and Plant Breeder, returned from
5 ao months’ leave of absence on January 13 and resumed duty on the same day.

As from January 1, the following Technical Assistants have been placed
on the Fixed Establishment : — D. D. Blackman. N. Persand, ('. Williams,
L. E. McKinnon, A. W. Sears and W. A. Bovell.

The Director of Agriculture visited Essequibo from January 10 to 13. lie
was accompanied by Mr. T. Bell who arrived in the Colony on December 13.
1938, to take up his new appointment as Agricultural Superintendent. Mr. Bell
has assumed duty in the Essequibo District and Mr. A. A. Abraham has been
transferred to the Berbice District.

A Staff Conference was held on January 19-20, when the various pro-
grammes of district work and experiments to be carried out during 1939 were
discussed. On the afternoon of the 20th., the Director and Mrs. Dash were “At
Home ” to the senior members of the staff.

The Annual General Meeting of the British Guiana Beekeepers’ Association
was held on January 24.

A meeting of the Advisory Board of Agriculture was held on January 2.">.

A meeting of the British Guiana Poultry Association was held on January
26 and the Annual General Meeting on February 27.

Mr. E. M. Petcrkin, Agricultural Superintendent, left the Colony on 28 days’
sick leave on January 28, returning on February 21.

In July last year a Royal Commission was appointed “ to investigate social
andxconomic conditions in Barbados, British Guiana, British Honduras, Jamaica,
the ^Leeward Islands, Trinidad and Tobago, and the Windward Islands, and
matters connected therewith, and to make recommendations ’’. This Commission

NEWS.

arrived in British Gniana on January 27, visited several districts and held public
hearings from January 30 to February 23. The Director of Agriculture gave
evidence on February 2.

Professor F. L. Engledow, the Agricultural Expert on the Commission,
visited the Head Office and the Divisions of the Department on several occasions,
and the East Demerara and Berbice Districts from February 21 to 23 with the
Director of Agriculture. The Director of Agriculture also accompanied the
Commission on a visit to the Essequibo Coast from February 2 to 4.

The Director of Agriculture has been appointed Chairman of a Committee
“ to enquire into and advise on the feasibility of establishing one or more-Dairy
Products factories and to furnish estimates of the capital and recurrent expendi-
ture of such a factory or factories ”. The other members of the Committee are
Hons. J. I. D’ Aguiar, C. R. Jacob, A. G. King, C. V. Wight, B.A., T. Lee, Dr. A.
Fulton, Messrs. R. V. Evan Wong, B.Sc., and H. A. Fraser, B.V.Sc. (Acting
Government Veterinary Surgeon).

Dr. D. W. Duthie, Chemist, has been attached in an advisory capacity to an
International Commission appointed to investigate the possibilities of settlement
of Jewish refugees in British Guiana. The members of the Commission are
Dr. E. C. Ernst (Chairman), Col. H. U. Nicholas, Dr. J. A. Rosen, Mr. E. C. Bataille,
Dr. A. Donovan, Sir Geoffrey Evans, Sir Crawford Douglas-Jones and Mr. D.
Holdridge (Secretary).

Mr. II. Parker, General Manager of Government Rice Mills, Federated
Miley States, who was detailed to investigate the possibility of the erection of a
central rice mill in Essequibo, and generally to consider rice milling problems in
the Colony, has submitted his report to Government. This report has been
published as Legislative Council Sessional Paper No. 3/1939.

The report of the Committee appointed to report on matters connected
with the establishment of a rice mill on the Essequibo Coast has been published
as Legislative Council Paper No. 4/1939.

Mr. E. R. Campbell, a principal of Messrs. Curtis Campbell & Co., Ltd.,
visited the Head Office and the Sugar Experiment Station on March 3. Other
visitors included Dr. E. C. Ernst, Dr. J. A. Rosen and Sir Geoffrey Evans, mem-
bers of the Commission on Jewish settlement.

Agriculturists generally will regret that His Excellency Sir Wilfred Jackson,
K.C.M.G. will be leaving the Colony shortly on medical advice. It is announced
that His Excellency the Governor of Barbados, the Hon. E. J. Waddington,
C.M.G., will adnfinister the Government in the interim.

PLANT AND SEED IMPORTATION.

Introductions by the Department of Agriculture for the period
November, 1938 to February, 1939.

Name

Quantity.

Whence Supplied

Economic.

Girigiri —Vigna oniata

i oz.

Agricultural Department.
Zaria, Nigeria.

Tobacco Seed

5 oz.

Coker*B Podigreed Seed Co.,
Hartsville, S.C.

Cinnamonum zelaniam

3 oz.

Curator, Royal Botanic

Gardens, Dept, of Agricul-
ture, Trinidad.

Cucumber — 3 varieties

£ oz. each

1 Messrs. Ferry-Morse Seed Co.,
California.

Pepper — California Wonder

do.

Egg Plant— Black Beauty

do.

Muskmelon — 4 varieties

1 do.

do.

Watermelon^ varieties

do.

Squash— 2 varieties

do.

Tomato — 3 varieties

1 do.

do.

Cane Cuttings — 7 varieties

cuttings of each

Plant Quarantine Station,

Dept, of Agriculture,
Trinidad.

Lespedeza — 5 varieties

£ oz. each

Messrs. S. H. Robertson & Son,
Northumberland Co.,
Virginia,

Camongay — M ori nga ole if era

4 lb.

ITnhersity of Hawaii,

! Honolulu, Hawaii.

Rice — 4 varieties

2 oz. each

Rice Breeding Station,

1 Karjat (Kolaba), India.

Rice— *4 varieties

Samples of each

Asst. Paddy Specialist, Rice
Kxpt, Station, Nagiua,N,P.,
India.

Ornamental.

Makita Nut —Farniartum laurinum

1 lb. 132 oz,

Director of Agriculture, Fiji,

Ivi Nut or Tahitian Chestnut—

1 no car pus edulis

do.

Flower Seeds
h

i lb,

Messrs. Hurst & Son, London.

METEOROLOGICAL DATA, 1938.

BOTANIC GARDENS, GEORGETOWN.

1938

Rainfall,

Number of Days of

Rain

1 *

i ~ .

Evapora-

Months

Inches

S fl

0 ©
0*1

.10 in
to

.50 in

.50 in.
to

1.00 in

1.00 in
to

2.00 in

Above
2.00 in

Total

Days

tion.

Inches

January

13.34

3.86

February

13.10

3.51

March

13.76

4 !

4.47

April

7.95

4.17

May

11.17

...

4.12

June

13.17

4 i

...

3.92

July

1 12.74

1 ,

4.12

August

14.96

| 22

3.86

September

1.83

• • •

7 |

5.60

October

3.48 |

5.31

November

5.12

4.18

December

6.36

...

4.27

Totals

119.00

83 1

225

51.39

AIR TEMPERATURE AND HUMIDITY IN THE SHADE.

BOTANIC GARDENS, GEORGETOWN.

Months

Air Temperature

Humidity

Mean

Maximum

Minimum

Mean

January

84.1

75.6

79.8

82.5

Febrnary

83.7

• 86.5

80.1

85.3

March

83.5

75.7

79.6

82.9

April

84.4

76 3

80.3

82.0

May

84.9

76.2

80.5

84.8

Jane

84.5

75.3

79.9

84.3

July

85.1

74.9

80.0

83.6

August

86.3

75.0

80.6

83.5

September

88.2

76.8

82.5

80.0

October

88.2

76.4

• 82.3

78.9

November

87.3

76.9

82.1

81.4

December

85.5

75.6

80.5

*82.2

Mean

85.5

75.9

80.7

82.6

WETTEST AND HOTTEST DAYS AT VARIOUS . STATIONS.

Stations

Wettest

Days

Botanic Gardens,
Georgetown

... ^ .

Feb. 11th

New Amsterdam,

May 6th

Public Gardens

Ouderneeming Indus-
trial School, Essequibo

March 16th

Hosororo,

N.W.l).

Feb. 14th

Rainfall,

Inches

1 Hottest

1 Days

Temperture

shade °F

4.31

1 Oct. 27th

1 !

91.0

3.92

1 Sept. 2nd

.1.

94.0

6.39

Nor. 8th,
9th, 10th

, 91.0

3.40

Aug. 10th
Sept. 10th

92.5

VoL X, No. 2.

June, 1939.

The

Agricultural Journal

British Guiana

PUBLISHED BY

THE DEPARTMENT OF AGRICULTURE

GEORGETOWN, BRITISH GUIANA

Price

••

• «

• •
• f

6d.

DEPARTMENT OF AGRICULTURE.

ADMINISTRATION

Director of Agriculture
Deputy Director

Clerical

Senior Clerk
Registrar of Banks

Class III Clerks

Probationers

Librarian

RESEARCH BRANCH.

Botany and Plant Pathology

Botanist — Plant Pathologist and Superintend -
ent, Botanic Gardens :

E. B. Martyn, B.A., A.I.C.T.A.

Technical Assistant:

N. Persaud

Chemistry

Chemist :

D. W. Duthie, M.A,B.Sc„ Ph.D., F.I.C.

Assistant Chemist :

C. L. C. Bourne (on leave)

Economics

Agricultural Economist :

H. D. Huggins, M.Sc., Dip. Agr.

Entomology

Entomologist :

L. 1>.‘ Cleare, F.R. Ent. S.

Technical Assistant :

C. Williams

Rice

Assistant Plant Breeder :

P. A. ChanCboong, B.Sc., A.I.C.T.A.

Sugar

(In co-qperation with the Sugar Producers)

Sugar Agronomist and Plant Breeder :

C. H. B. Williams, M.A., A.I.C.T.A., Dip.
Agr.

Laboratory Assistants :

H. B. Singh

A. V. Wan-Ping, Dip. Agr.

Statistical Assistant :

J. B. Bourne, F.S S.

Prof. The Hon. J. Sydney Dash,

B.Sc. (Agric.)

... (vacant)

L. D. Cleare, F,R, Ent. S. (acting)

Staff.

J. F. Irving, M.C.

W. G. Delph (on leave)

A. A. Thorne (acting)

C. A. Lashiey (acting)

Miss D. M. Terrill

Miss M. Cheong
P. 0. Jackson
-J S. A. Adams
I Mi as S. Lord
' Miss B. Delph

Miss Y. Chan-Choong

LIVESTOCK BRANCH

Veterinary Surgeon :

Vacant

H A Fraser, B Y Sc. (acting)

FIELD BRANCH

Agricultural Superintendents :

Berbice— A. A. Abraham
Demerara, East— E.M. Peterkin
Demerara, East Bank— H. D. Huggins,
M.Sc., Dip. Agr.

Demerara. West — E. G. Benson, B.Sc.,
A.I.C.T.A., Dip. Agr.
Essequibo-T. Bell, B.S.A., A.I.C.T.A.

Assistant Agricultural Superintendent:
Berbice— E. M. Morgan

Agricultural Instructors :

Berbice — 0. F. J. Churaman, Dip. Agr.
Botanic Gardens — H. A. Cole
Demerara. East— 0 C. Dowding, F.L.S,.
F.R.H.S.

A griculiural A ssixtants :

Demerara, East — J. Indrobeharry
Essequibo — H. B. France

Technical Assist ants :

Demerara, East— W. A. Bovell

Essequibo — A. W. Sears

North West District— L. E. McKinnon

Sugar

Field Manager (Central Station)

C. Cameron

Field Assistants :

L. A. Fmrte
B. A. McArthur

METEOROLOGICAL BRANCH

Technical A instant i
D. D. Blackman

Meteorological Assistant :

J. E. Isaacs

RICE GRADING BRANCH

Grading Inspector :

H. E. H. Gadd

Technical Assistants :

B. R. Boss
G. L. Leitch

ADVISORY BOARD OF AGRICULTURE

Director of Agriculture, Chairman, ex officio .

Deputy Director of Agriculture, Vice-Chairman, ex officio .

Hon. Peer Bacchus ... ... ... \

Hon. R. E. Brassington ... ... ... )

Hon. J W. Jackson ... ... ... [

Hon. F. J. Seaford, o.b.e ... ... ... > Members

Mr. S. Andries ... ... ... ... I

„ B. B. Hunter ... ... ... 1

„ W. H. Richards ... ... ... '

SUGAR EXPERIMENT STATIONS’ COMMITTEE.

Director of Agriculture, Chairman, ex-officio.
Hon. M. B G. Austin, o.b.e.

Mr. G. M. Eccles
„ J. C. Gibson

„ A. Murison

„ L. Lywood (acting for Mr. R. E. Rhodes)
„ J. Bee

Georgetown
Pin. Blairmont
Messrs. Booker Bros.

McConnell Co. Ltd.
Pin. Uitvlugt
Pin. Leonora
Pin. Albion

Represeattaf
the Sugar
Industry
which naia-
talas the
Statioas

CO-OPERATIVE CREDIT BANKS’ BOARD.

Director of Agriculture, Chairman, ex-officio.
Hon. J. W. Jackson
Rev. A. E. Dyett...

Mr. 0. Farnum
.. J.L. Wills ...

Members

DISTRICT AGRICULTURAL COMMITTEES

EAST DEMERARA

Director of Agriculture, Chairman

District Commissioner

Deputy Director of Agriculture

Hon. J. I. deAgukr

Hon. E. M. Walcott

Mr. S. Andries ...

... \

Members

„ M. Ghani
., W. H. Richards
„ J.E. Wills ...

WEST

DEMERARA

Director of Agriculture, Chairman

District Commissioner

Deputy Director of Agriculture

Hon. J. W. Jaokson

Dr. the Hon. J. B. Singh

Mr. R. P. Carryl
,. J. C. DaSilva
„ B. Hunter

:: '

Members

>. A. Murison ...

„ W. Ramdeholl
n A. Rayman ...

CONTENTS

(VOL. X, No. 2.)

Page

EDITORIAL— 47

BERBICE COUNTY EXHIBITION— 49

ORIGINAL ARTICLES.

The Amazon Fly {Met agon -
isti/lum minense, Towns.)

in British Guiana ... L. D. Cleure, F.R.Ent.S. ... 55

Testing Large Numbers of
Rice Varieties by the

Quasi-Factorial Method ... P. A. Chan-Choong, B.Sc., A.I.C.T.A. 78

Double versus Single Plant-
ing of Sugar-cane ... C. H. B. Williams, M.A., A.I.C.T.A. ,

Dip. Agr. and

L. A. Forte ... ... ... 89

Catalogue of the Lepidophra
rhopalocera (Butterflies)

of British Guiana. (Could.) ... Arthur Halt, F.R.Ent.S. ... 96

NOTES.

The Foreshore Vegetation

East of Georgetown ... ... ••• ••• ••• 105

Plant Inspection Service ... ... — ••• ••• 10?

PLANT AND SEED EXCHANGE ... ... ... * ... 108

METEOROLOGICAL DATA ... ... ... ... 110

Contents — Continued.

ILLUSTRATIONS

Facing Page

Plate

I. — Fig.

1 — The Amazon Fly, Metagonistylum mineme
Towns, x 6.

»y

Fig.

2 — Sugar-cane Moth-borer Investigation
Laboratory, 1931-35, at Sugar Experiment
Station, British Qniana

Page

Fig.

1 — Sketch of Sixtus photo-electric exposure
meter showing intensity of light at which
matings of Metagonixtyluin occur

Facing

Page

Plate

II. — Fig.

1 — The Seaward Edge of the Courida at
Liliendaal

106

»*

Fig.

2— Rice Grass West of Kitty Jetty, May, 1939 ...

106

The

Agricultural Journal of British Guiana.

June, 1939.

EDITORIAL.

SELF-SUFFICIENCY.

Few movements are affecting modern agriculture more than the world
wide trend towards self-sufficiency. The arguments for and against this move-
ment are no longer heard as often as formerly, because the concept, whether
or not approved in principle, must in most cases be given effect to in practice.

An illustration of cause and effect of this self-sufficiency movement is
given by the world rice trade. There has been, within the last ten years, a great
increase in the production of this crop in several major importing countries
which have been compelled to regulate their imports in the interest of national
economy. Such development has been particularly marked in the raw material
exporting countries of the far East and South America. Thus when Malayan
exports of rubber and tin were high, rice imports were large; as exports of
rubber and tin fell during the world depression unemployment resulted and rice
imports declined. In recent years, several of the Governments of South
American countries — notably Argentina, Colombia and Peru — have increased
rice import duties in order to increase .home production. In Brazil extensive
loans to rice growers, the systematic employment of rice specialists and other
large scale spending programmes, have done much to increase domestic output.
Such have been some of the causes inducing self-sufficiency in rice and the
results have been equally subtle and far-reaching. Those countries which pre-
viously supplied the world’s markets with rice are meeting with a curtailed
demand. It is clear that these countries will, in turn, have their income
restricted and so must themselves resort to self-sufficiency in one direction or
another. Thus the vicious circle continues and it is in this situation that

British Guiana with many other countries of the world finds itself today.

When an agricultural exhibition was held in British Guiana recently it was,
therefore, not surprising to observe that a focus of attention was the indication
given by the exhibition in regard to the Colony’s self-sufficiency development.

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[X, 2.

The exhibition was held in New Amsterdam, Berbice, on Friday and Satur-
day, April 21 and 22. In spite of heavy rains causing flood conditions in
many areas shortly before the exhibition, an excellent collection of agricultural
exhibits of all kinds were on show. His Excellency the Governor, Sir E. J.
Waddington, K.C.M.G., O.B.E., put into words the view of everyone when he
emphasized how surprised he was at the fine display of exhibits which he had
seen in the various stands “ despite the very abnormal weather conditions.”
Elsewhere in this Journal is given an account of the Exhibition, where it
will be seen that special mention was made of what is being achieved in regard
to making the Colony more self-sufficient. The Director of Agriculture said :
“The general display of garden produce is worthy of mention as it shows the
great interest taken in the movement towards self-sufficiency, and Berbice in the
past has been rather behind in this respect. This I feel reflects credit on
the growers and I am sure the advantages of the Agricultural Bias scheme are
becoming apparent”.

The Berbice County Exhibition was in every way a great success, as was
its predecessor in Georgetown, the Jubilee Agricultural Exhibition. In British
Guiana, it is still a formidable task to organize and' bring to a successful con-
clusion projects of this type, but with each success the task is reduced. It is
evident that 'in this Colony there is now being built up, surely, if slowly, an
exhibition tradition which provides the chief urge for co-operation between the
several classes and interests in the community.

An agricultural exhibition is helpful in many ways. The producer gives of
his best and sees by comparison how his best can be made better; the public
takes away impressions which, by attracting attention to home grown products,
makes it easier for the Colony to expand its self-sufficiency programme.

BERBICE COUNTY EXHIBITION.

The Berbice County Exhibition was held in Colony House Gardens, New
Amsterdam, Berbice, on Friday and Saturday, April 21 and 22, 1939. The
Exhibition took place after having been postponed on three previous occasions
and even on the day previous to the date finally fixed, continuous rains
threatened to compel abandonment. Not only did weather on the 21st turn out
to be fine but agricultural products of all kinds poured into the exhibition
grounds in quantity. It was only on the morning of the day itself that the
Organizing Committee realized what a great success the exhibition was. It
could be seen, from early in the day, that visitors to the show who came to be
entertained, remained to be impressed.

Exhibits were invited under the 12 following classes :

1. Sugar Cane (open to cane farmers) ; 2. Rice; 3. Livestock; 4. Coconuts:
5. Coffee; 6. Provision Crops; 7. Vegetable Crops; 8. Fruit; 9. Cacao; 10.
Miscellaneous Crops; 11. Home Manufactures; 12. Beekeeping.

Seven stands were erected. One stand, reserved for the various Divisions
of the Department, displayed exhibits of an educational nature. A special
feature of this stand was the use of diagrams, models and simple means of
illustration to render the propaganda efforts as effective as possible. A
separate stand, faced with split sugar canes, prepared by the Sugar Experiment
Station, contained educational exhibits relating to sugar production. In
addition, there were three large stands to house competitors’ agricultural
exhibits and two for livestock entries. In certain classes so many articles were
received that they had to be placed on the ground near to their respective
booths. It is estimated that 5,000 persons visited the exhibition and that
approximately 1,000 exhibits were on view.

In the sugar educational exhibit, several diagrams bearing on the different
aspects of sugar-cane cultivation and the inter-relationship of the industry
with the Colony’s economic structure were on view. During the last decade
the Colony’s yield of sugar per acre has approximately doubled; different
varieties and diagrams relating to the cultural practices which have brought
this about provided the public with a good deal of useful information. The
Berbice sygar estates co-operated by exhibiting clumps of cane varieties and
samples of manufactured products.

In the rice section, a wide range of padi and rice samples helped to give
the grower an impression of the various considerations to be borne jn mind in
regard to different varieties. There were also diagrams in connection with
the rice breeding work showing the variety status and the progress in the estab-
lishment of pyre line areas.

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

EX, 2.

In the entomological section, the chief feature was a series of large posters
showing in colour the different stages in the life history some of the Colony’s
important pests together with control measures. Specimens of the Amazon fly
in a breeding cage helped to give an indication of the method that has been,
found effective in rearing this fly in sufficient numbers to reduce the damage
caused by moth borer to the present level. Several types of spraying machines
were on view.

In the horticultural and plant propagation section plants of economic value
formed a special feature together with demonstrations relating to the methods
to be adopted in budding and grafting. Various simple hints in regard to
nursery practices were also given. A special tobacco demonstration showing
the different stages in the production of the crop up to and including the curing
stage appeared all the more realistic with the inclusion of a model tobacco barn.
The barn was made to scale and included flues, wires for hanging and even
small tobacco leaves.

The chemistry section illustrated various features of soil work, including
soil-less culture of vegetables and flood fallowing, and demonstrations in con-
nection with parboiling and rice processing. <

Standardised beekeeping equipment was shown with the object of drawing
the attention of rural beekeepers to the advantages obtained from modern
practice and appliances.

An effort was made in the economics section to indicate by diagrams some
of the chief trends in economic progress during recent times. Attention was,
for example, drawn to the remarkable expansion in the exports of cattle and
poultry to Trinidad within the last three years.

Leaflets especially those which would be considered of practical application
to the farmer were on show and distributed to those interested.

The Department of Agriculture is indebted to the Exhibition Com-
mittee for the assistance given in connection with organization arrangements
Members of the Committee were :

Members of the Advisory Board of Agriculture with

Hon. J. Eleazar, Mayor of New Amsterdam

Hon. E. A. Luckhoo, O.B.E.,

District Commissioner, Berbice,

Messrs. G. M. Eccles, H. F. Chapman, F. F. Ross, Jas. Bee, J. C. Gibson,
S. J. F. Blanchard, T. P. Jaundoo, C. Farrar, II. T. King, J. Haly, Rev.
A. E. Dyett, Canon Gregory and the Agricultural Superintendent,
Berbice.

Thanks are also due to the Militia Band which was in attendance on both
days.

BERBICE COUNTY EXHIBITION.

The following is an account of the opening ceremony :

DIRECTOR OF AGRICULTURE'S REVIEW

Your Excellency, 'Your Worship, Ladies and Gentlemen : — I speak on behalf
of the Berbice Exhibition Committee. My most important duty to-day — and it
is a real pleasure, Sir — is to welcome warmly Your Excellency and Mrs,
Waddington; I will not say to New Amsterdam as that would be stealing the
Mayor’s thunder and I am sure he will wish to do that himself.

As agriculturists we are glad to have you once more amongst us, and we
do know that Barbados has spared you most grudgingly, in spite of the fact that
Barbados frequently claims British Guiana as a daughter Colony. Feelings
have been a little strained recently because we have had the impudence to claim
that we could rival her in the production of that delectable table delicacy — the
sweet potato. Anyhow, Sir, we hope when you return you will be able to say
that the claim is abundantly justified.

Now, this Exhibition, like most others with which I have been acquainted
in this Colony, has not been without its vicissitudes. Planned to take place
originally in 1937 it was postponed to April, 1938, on account of labour troubles
in the Colony; unfortunately prolonged excessive rains caused a further post-
ponement to April, 1939. Then it had to be deferred for one week on account
of the recent abnormal rains.

Looking back to previous records I find that April has usually been asso-
ciated with Exhibitions although some have been held in the summer months.
The 1935 Jubilee Exhibition which was most successful was an April Show.
April is a good month because it is possible to stage practically everything
grown in the Colony at this time of the year.

Coming more particularly to the display before you I think it will be
admitted that it is most gratifying — the stands are laden with good things and
would have been fuller still if the floods had not destroyed many ground pro-
vision areas, especially on the West Coast, Berbice, but the Committee felt that
to go on postponing the Show could only have resulted in great discouragement
and dissatisfaction to the majority of farmers. I must say that it is a source
of great satisfaction to note the keenness and enthusiasm generally. Much of
the detailed work has been carried out by my Berbice staff led by the Agricul-
tural Superintendent, Mr. Abraham, east of the river, and Mr. Morgan, west of
the river. Their labours have been justified by the results. It is hoped to
run special competitions in the affected areas to aid their re-establishment.

I do not wish to detain you at any length, but I must refer to one or two
special features. The general display of garden produce is worthy of mention
as it shoMrs the great interest taken in the movement towards self-sufficiency
and Berbice in the past has been rather behind in this respect. This I feel
reflects credit on the growers and I am sure the advantages of the Agricultural
Bias scheme are becoming apparent. In this connexion I wish to mention par-
ticularly the splendid efforts of Mr. Fraser, Head-Master of Friends Scots
School, who was one of the first batch of teachers turned out by the Agricul-
ture Department. I will read you what Professor Engledow wrote in his school

52 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 2.

log-book after seeing him at work with his boys whom he asked many questions
and from whom he received satisfactory replies :

“ 15.2.39. I found the garden well managed. The boys had a far better
understanding of the cultivation and management of the land than I have
usually found in schools I have visited in the Caribbean. The teaching should*
be of good value in a district in which food and vegetable crops are grown.”

(Sgd.) F. Engledow,
West India Royal Commission.

Mr. Fraser has been awarded the Cup presented by the Royal Bank of
Canada.'

I cannot refrain also from mentioning the minor crop efforts of Mr.
Blanchard, Pin. Lochaber. He has been persevering for some time now with
tobacco and tomatoes, and encouraging his tenants to improve their livestock.
The heavy rains have dealt him a great blow but he is not discouraged and it
gives me great pleasure to announce him the winner of the Cup presented by
Barclays Bank for his initiative and enterprise.

While on the subject of tobacco which is receiving increased attention as a
result of the recent demonstration by local cigarette factories, I would direct
your attention to the educational exhibit in the Department’s stand. It depicts
the stages of cultivation right through to curing by heat and there is a model
flue barn, the work of Mr. MacArthur, one of our subordinate staff.

I will not say much of Sugar and Rice. Progress in these industries is
well known and they are fully represented on this occasion. The Sugar stand is
splendid and the staff of the Experiment Station have done good work.

In connexion with Rice efforts in Berbice I am pleased to announce the
award of His Excellency the Governor’s prize of $10 to Mr. Ramjohn. Please
do not fail to see Mr. Ramjolin’s exhibits.

Another effort which is being specially rewarded is that of the Mental
Asylum where very useful work is being put in on vegetable and fruit-growing.
My own humble prize of 1,000 local cigarettes will be handed over to the Medical
Officer in charge for distribution to the men who have supplied a number of
exhibits.

The exhibits in the Livestock section, Home Manufactures and Fruit have
all reached a high standard but time will not permit any detailed mention.

I hope you will devote some time to the educational exhibits put up by tho
Department of Agriculture. A visit to the stand will repay you.

* It is customary at this stage to announce the winners of the Diploma of
Merit awarded by the Department of Agriculture for exhibits of outstanding
merit but the list is not yet complete and will be published later.

BERBICE COUNTY EXHIBITION.

Finally, I desire to tnank from the bottom of my heart all those who have
contributed in any way to the success of the Exhibition, especially farmers and
cattle-raisers who have suffered great hardship recently.

I now have much pleasure in asking Your Excellency to open the Exhibition.

H.E. THE GOVERNOR OPENS EXHIBITION

His Excellency said that he was very surprised at the fine display
of exhibits which he had seen in the various stalls. He was told that about 12
years ago an exhibition was held in New Amsterdam during the regime of His
Excellency Sir Cecil Hunter Rodwell and though that one was of a very high
standard this exhibition, despite the very abnormal weather conditions he was
told, was not one whit behind.

He congratulated Mr. W. A. Fraser of whom Professor Engledow had
spoken so highly on having annexed the beautiful silver trophy presented by the
Royal Bank of Canada for his fine display of garden produce. He also congrat-
ulated Mr. Blanchard who won the Cup presented by Messrs. Barclays Bank for
his initiative and enterprise. He also thanked the Mayor and Town Council
for the help they had given and also Professor Dash and his Staff for all that
they had done.

The Hon. J. Eleazar, Mayor of New Amsterdam, in thanking His Expel-
lency for coming to declare the show open, made reference to the abnormal
weather conditions and the need for proper drainage for farmers. Despite the
weather, however, they were able in two weeks to bring off a fine exhibition.
He thanked all those who had helped to make the show a success.

Mrs. Waddington presented the Cups to the winners with whom she shook
hands and whom she congratulated. She was presented with a beautiful
bouquet by little Miss Cynthia Harrington.

His Excellency thereafter declared the exhibition open.

DIPLOMAS OF MERIT.

An announcement has since been made of those exhibitors who have been
awarded Diplomas of Merit. The list is as follows : —

Name

Ramjohn, Corentyne

Rash Beharry & Co., Essequibo

Rev. A. E. Dyett, Corentyne

Exhibit

Long grain padi and rice — Demerara
Creole Variety.

Whole grain super rice packed for
export — Blue Stick variety.

Holstein Bull,

Harold Ramdehpll, New Amsterdam Capons.

agricultural Journal of britIsh guIaNA.

Auchlyne Scots School, Whim, Cor-
entyne

Friends Scots School, E.B., Berbice
River. 1

No. 5 Congregational School, W.C.,
Berbice

Henry Chan, Rosignol, W.C., Berbice

Plantation Providence, Berbice

Emily Collins, Golden Grove, E.C.,
Demerara.

Cecilia Robinson, Enmore Front,
E.C., Demerara.

Domestic Science Centre, New Am-
sterdam, Berbice

Georgetown Prison

British Guiana Broom Factory,
Georgetown.

tx,a.

School Garden Produce.

Grapefruit — produce of Pin. Plegt
Anchor, Berbice River.'

Limes and lime products.

An assortment of meals.

An assortment of preserves.

Fibres, Ropes and Mats.

Brooms.

ORIGINA L AR TICLES.

THE AMAZON FLY ( ME TAGONISTY L UM MINENSE,
TOWNS.) IN BRITISH GUIANA*

By L. D. CLEARS,

Entomologist , Department of Agriculture , British Guiana . t

Contents.

PAGE

1. History of the project 55

2. Introduction of the parasite 5fi

3. Bionomics 58

4. Species of Diafraea attacked 65

5. Colonisation in British Guiana ... ... 66

6. Cost of introducing the parasite 72

7. Parasitism of D . xarcharalix in rice and other host-plants 72

8. Status in 1937 73

9. Shipments of the parasite to the West Indies 75

10. Acknowledgments 76

1. History of tiie Project.

In 1932 on an expedition in Brazil, Dr. J. G. Myers, of the Imperial
Institute of Entomology, while in search for suitable parasites for introduction
into this and other colonies in the West Indian area, discovered the Tachinid fly
Metagonistglum minense. Towns., known generally now as the Amazon fly, as
an important parasite of Diatraea saccharalis , F., in the vicinity of Santarem on
the Amazon, and as the result of his investigations there, formed the opinion
that it would be a suitable parasite for introduction into British Guiana.

On his return to British Guiana in January 1933, Dr. Myers acquainted the
Sugar Producers’ Association of this Colony of his discovery, and suggested the
utilization of the parasite in the cane-fields of British Guiana. The Association
undertook to bear the cost of the introduction of the parasite and provided a
sum of £2,000 for this, the fund being administered by the Director of
Agriculture.

In May 1933 Dr. Myers, accompanied by Mr. A. H. Pickles, Entomologist
of the Sugar Investigations Committee of Trinidad, and Mr. L. C. Scaranmzza of
Cuba, left Georgetown for the Amazon district by way of the hinterland of
British Guiana for the purpose of making collections of the parasite for shipment
to this country. The first shipment of the parasite arrived in British Guiana on
30th August, 1933.

# Reprinted from Bullentin of Entomological Research , Vol. 30, Part 1, April 1939.
t Seconded as Entomologist-in-charge, Sugar-cane Moth-borer Investigations, Colonial
Development F^nd, July 1931 to April 1935.

56 ac&icultoeal journal or &Rmsa guuna. tX 2.

An account of the discovery of the fly, the return journey to Brazil and the
collection and shipment of the insect from Brazil to British Ouiana, has been
published already by Myers (11 ).

The present account deals, therefore, only with such of the work as was
undertaken in British Guiana either by the writer personally or directly under
his control, namely, the receiving of the parasite in this country and the rearing
of the flies from the initial shipments, the subsequent rearing of large numbers
of flies for the colonization of the sugar-estates of the Colony, including the
training of East Indian laboratory assistants for work on the sugar-estates and
the supervision of the rearing work on the estates. This work extended over a
period of twenty months, from September 1933 to April 1935. Since then, the
writer has been closely associated with the Amazon fly situation in the Colony
and during the past year (1937) was engaged on a status survey of the fly in
British Guiana. In conjunction with Myers’ paper the present account should
form a more or less complete record of the introduction and establishment of
this insect in British Guiana.

The introduction of the Amazon fly into British Guiana was the first im-
portation of this insect into any country and its first use in biological control.
Since then *the Amazon fly has been introduced into the Islands of St. Lucia,
Trinidad and Puerto Rico from material bred m British Guiana, and into the
island of Antigua from St. Lucia. These introductions do not come strictly
within the scope of this paper so will merely be touched upon in another section.

2. Introduction of the Parasite.

Shipments received. —The collection and transport of the insect to British
Guiana has been dealt with fully by Myers (11) and need not be repeated here.

The first trial consignment of puparia was received in Georgetown by
registered air mail (Pan-American Airways) on 30th August, 1933. Of the 57
puparia sent on that occasion, flies had emerged from 31 en route and the insects
were already dead when the package was received, and from the remaining 26
puparia only three flies were secured and a fourth died during emergence. The
air mail on this occasion was 23 hours late on its schedule in arriving at
Georgetown, and this, no doubt, to some extent accounted for the high mortality
of this consignment. The later consignments showed considerable improvement
as regards the percentage of flies secured.

From a total of 3,000 puparia shipped from Brazil, 1,409 flies, or 46.9 per
cent, were secured in British Guiana ; 935 puparia (31.2 per cent.) failed to
produce flies, while 592 flies (19.7 per cent.) emerged and died in transit, and
64 puparia (2.1 per cent.) produced secondary parasites ; making a total of 1,591
or 53.1 per cent, “failures.”

Considering the long voyage, the difficulties of transport, and the narrow
margin which the pupal period of the insect allowed to accomplish it, the
number of flies secured must be considered good.

Flfc. 2,— Sugar-cano Moth-borer Investigation Laboratory, 1M1 — 35,
% at Sugar Experiment Station, British Guiana.

THE AMAZON PLY (ItETAGONISTYLU M M 1 NENSE, TOWNS.) IN B&mstt GUIANA. 57

Receiving and handling the material — The packages containing the puparia
after coming down the Amazon in a special launch were posted by registered
air mail at Para. The arrival of the launch at Para was made to synchronise
with the departure of the Pan-American Airways plane which runs a regular
weekly service between that port and Miami, Florida, U.S.A., via French, Dutch,
and British Quiana and certain West Indian islands, and in this way a minimum
of delay was obtained.

The time of approximate arrival of the plane at Georgetown being previous-
ly ascertained, the writer took charge of the packages personally at the General
Post Office, Georgetown, as soon as the mail was recei\ed there, and conveyed
them immediately to the laboratory.

The puparia in the earlier shipments were packed in damp fibre, but later
when bagasse* that was sent from British Guiana was available, in that material,
in 2 oz. ointment tins, the number of puparia in each tin varying somewhat
according to the total number in the shipment, the maximum being about fifty
in any ono tin. The ointment tins were then packed in a liberal amount of
cottonwool in a cardboard box and the whole wrapped.

As the journey down the Amazon from Santarem to Para occupied some
six days by launch, and the plane trip from Para to Georgetown a further day
and a half, and as the puparia had to be collected some days before, it was natural
that there should have been a fairly high percentage of adults emerging en
route . The majority of such flies died before the receipt of the packages and
constitute 37.2 per cent, of the total failures. Some of these flies, probably
those which emerged only a few hours before the actual receipt of the
packages at Georgetown, were always found crawling about in the tins when
they were opened and it was possible to save a number of these.

On arrival in the laboratory the packages were opened within a special
glass-sided cage in order to secure any secondary parasites that might have
emerged in transit, and the newly emerged flies which were found to be still
alive were collected and transferred to suitable cages. The puparia were then
sorted and those from which flies had emerged removed, the remainder being
transferred, five at a time, to cylindrical glass lamp-chimneys of 2i inches
diameter, one end standing in damp sand and the other being plugged with
cotton-wool. In these the flies subsequently emerged and were transferred
thence to cages.

From the earlier consignments some of the flies were released within a day
or two of emergence, and some retained for rearing trials in the laboratory.

Secondary parasitism . — In spite of the care exercised at the sending end,
as was to be expected, a small number of the puparia received produced
secondary parasites. Of the 3,000 puparia received in shipments,. 64, or 2.1

•Sugar-cane after the mice hid been extracted. With modern manufacturing methods it
la reduoed to a fin# sawdust-like form.

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

tX, 2.

per cent., produced such secondary parasites. Three secondary parasites were
thus secured, namely, Melittobia sp. (Eulophidae), Trichopria ( Ceratopria ) sp.
(Diapriidae), and Signophora dipterophaga, Girault (Encyrtidae), the last of
which, already known as a secondary parasite of Leskiopalpus ( Stomatodexia )
diadema, Wied., in British Guiana, being predominant.

3. Bionomics.

The fly Metagonistylum minense was first described by Townsend (19) in
1927. Subsequently it was redescribed by Aldrich (1). In 1933 Monte (10)
recorded it as attacking Diatraea saccharalis.

The only country in which the insect is known to occur naturally at
present is Brazil. In that country, however, its range is considerable. First
recorded from the Lower Amazon district, it has been discovered recently by
Harland (9) in the vicinity of Sao Paulo. Harland suggests that the insect
in the Sao Paulo area is a distinct biological race.

The adult of Metagonistylum minense is an insect of striking and char-
acteristic appearance, and even in a general way ( is not likely to be mistaken
for other flies parasitic on Diatraea, the large and prominent antennae, carried

extended in front of the head, serving readily to distinguish it in the field.

The fly varies considerably in size, and may measure from 6.5 mm. to
10.0 mm. long, and is about 3J to 4 times as long as it is broad. The antennae
are black in colour, large and prominent, and protrude in front of the head;
the front of the head is considerably produced and cone-shaped; the thorax
is bluish-gray with two darker longitudinal stripes; the abdomen reddish-
brown with a median darker stripe, showing bluish-gray reflections in certain
lights, the last segment being much darker, and there are many strong
bristles; the wings are large and strong and of a smoky brown colour, the
legs are black. There is no difference in size between the sexes, but they
may be usually distinguished superficially by the shape of the abdomen, the
male abdomen being rather more blunt and more bristled than that of the
female.

The newly emerged larvae are small, measuring only 0.6 mm., and very
active. When they become fully grown they may measure from 12.1 mm. to
13.9 mm. in length.

The puparium when first formed is chestnut-brown, but becomes darker
later as development proceeds; it is oval in shape, both ends being evenly
rounded, and may vary from 5.4 mm. to 8.8 mm. long and from 2.2 mm. to
8.1 mm. broad depending upon the food available for the larva. It may be
readily distinguished from the puparium of the other fly parasites of Diatraea
by means of the anal spiracles.

I . Life-history. — Myers (12) has given a short account of the life-history
and bionomics of the fly, based partly on rearings on the Amazon and partly
on the work in British Guiana. During the course of the very extensive

tttE AMAZON PLY (MfifAGbMStYLUM M1NENSE, TOWNS.) IN BRITISH GUIANA. 59

laboratory rearings which were carried out in British Guiana the writer was
able to obtain considerable data on the life-history and bionomics of the insect
and these will now be given.

The total life-cycle of the insect varies from 10 to 27 days, of which 5 to
9 days are spent as a larva within the host and 7 to 9 days in the puparium.
Laboratory rearings of 20,556 individuals gave a mean life-cycle of 16.77 days.

Of 20,666 flies, 6,132 (29.8 per cent.) had a total life-cycle of 16 days, in
26.8 per cent, it was 17 days; in 15.0 per cent, it was 18 days; in 13.3 per
cent, it was 15 days; and in 6.3 per cent, it was 19 days. So that for 91.2
per cent, of the flies the life-cycle was between 15 and 19 days. The life-cycle
varied from 10 days (0.39 per cent.=8 flies) to 27 days (0.001 per cent.=l
fly.)

The adult female deposits eggs which hatch immediately on deposition,
the empty egg-shell being at times plainly visible to the naked eye, and two
or three larvae are so released at a time. Deposition takes place either at
the entrance of the Diatraea tunnel or on the cane-stalk in the vicinity of
tunnels, and the young larvae may wander about considerably before finding
a host, while doubtless a very large proportion never do encounter a Diatraea
larva and consequently perish. One or more larvae may also enter a single host
larva.

When fully developed the larva leaves the host, which has by that time
died and putrefaction set in, and pupation occurs either within the Diatiaca
tunnel, behind a broad leaf-sheath of the cane, or the larva may fall to the
ground where pupation takes place. From five to twelve days is spent in the
puparium, after which the adult fly emerges.

Mating . — Mating occurs from a couple hours after the emergence of the
fly from the puparium to as long as six or more days after this. It takes
place with the insects in the resting position, quite often with the head down-
wards, but the body of the female is rather closely appressed to the surface
on which she rests. The body of the male is generally in the same axis as
that of the female, the forepart being raised somewhat on its forelegs and
the abdomen depressed so as to make contact with the female. During coition
the male sometimes makes violent convulsive and apparently excited move-
ments as if to secure better connexion. The genitalia of the male are visible
during coition.

Mating commences at times with a short struggle, but at other times
takes place quietly, the male merely approaching the female and getting into
position. There appears, however, usually to be a preliminary “ love play ” in
which the male strikes the female a number of blows with his abdomen, in a
hammer-like manner and apparently with some force; meanwhile the genitalia
of the male are extended visibly, the female offering no resistance and
apparently accepting it as a normal proceeding.

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

tX,2

When the female is ready to accept the male she raises her abdomen and
union is almost immediately effected. For a while after copulation commences
the antennae of the male are held close against the front of the head but later
are extended, sometimes first one and later both ; the antennae of the female are
extended all the time.

The time spent in copula is usually from ten to twenty minutes, but
matings as short as two minutes and as long as seventy-seven minutes have
been recorded, the average duration in 1,015 matings having been 15.98 minutes
(Table I).

Table I.

Shorn tig Duration of Matings <>J Metagouistylum minense.

Copuhtiou 11*3 i 19.4

Minutes

Sept

! Oct

Not

| Dec,

Jan

Feb

Mai

A pi

Maj

1 June

- 5

-to

— ir>

3<)

412

- 20

270

-25

—

1 3 | 3

>(>

129

- 30

1 1

-35

1 2

-40

—

-45

—

- 50

—55

-GO

- G5

i -

—

— i

—

-70

— |

—

1 —

-75

— |

—

1 —

1 1

' 1

No. Pairs

104

, 115

102

144

139

14G

’ 139

1,016

Total minutes

195

421

1,226

1,2*8

1 1,873

1,541

2,321

2,491

2 600

2,252

16,208

emulation
minutes—
average ...

13.9

15.0

11.8

15.3

36.3

151

16.2

17.9

178

16.2

15.98

THE AMAZON FLY (MBTAGONISTYLUM MINENSE, TOWNS.) IN BRITISH GUIANA. 61

It was observed early in the rearing work that a male would mate on more
than one occasion, both with the same female and with different females.
When mating occurred more than once with the same female there was either
a complete separation of the flies with a loss of position of the male, or only a
short interval in what could be mistaken for a continuous mating, the male
remaining in position on the female during this time. Mating with different
females on different days occurs also, and the data obtained in such instances
showed that each female was fertilized, but there was a definite indication that
the number of larvae produced gradually lessened.

Females also have been observed to mate more than once, but in every such
instance these matings occurred on the same day with short intervals only, and
it would appear that such matings must be regarded as incomplete matings in
the first instance rather than independent matings as in the males.

The all-important factor in mating is the intensity of the light. In
previous work on Tachinidae some stress has been laid on the size and type
of cage used for the flies in order that mating may take place rapidly. When
work with this insect was commenced, bearing this in mind, comparatively
large cages were used, but it was soon found that mating occurred frequently
in much smaller cages, and it became evident that some other factor was
involved. Investigation suggested intensity of light, and further work which
followed confirmed this. Later, when the correct intensity of light was ascer-
tained, it was found possible to obtain matings at almost any time of the dav
and in receptacles of any size, provided that the required intensity of light was
obtainable, so much so that for laboratory purposes females were usually mated
in 6 X 1 inch specimen tubes.

When mating is about to take place, as soon as the required intensity of
light is attained the flies become active, this activity being a peculiar restless
movement which is characteristic. Should the light either increase or decrease
in intensity this activity at once ceases.

At first in order to standardise conditions the intensity of light was tested
by means of a photographic exposure meter of the actinometer type, for want of a
better instrument. The meter used was a simple comparator type, the Watkin’s
Ilee Meter, which gave quite satisfactory results for general purposes.

It has been possible since to carry out tests of the intensity of light at
which mating occurs with a Sixtus photo-electric meter. From a series of such
tests it has been found that mating occurs in lights of an intensity within the
comparatively narrow limits, on this meter, of the upper portion of the 25 area
(needle in line with figure 4 on lower scale) and the lower portion of the 50
scale (needle at end of 4 area on lower scale) but usually about the upper end of
the 25 area. In lights of intensities of either below or above the mating range
the flies are usually quiet, thus at about the lowest quarter on the 25 area

62 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 2.

(25.1—25.2), as the lower extremity of the scale, and the highest quarter in the
50 area (50.6—50.7), as the upper extremity, mating activity ceases.

Fig. 1.— Sketch of Sixtus photo-electric exposure meter showing intensity of light
(shaded area) at which matings of Meta</oni*tt/lu/n occur. The details of the meter with
regard to emulsion speeds and f/valueg are not shown ns they have no bearing on the intensity
of light with regard to matings of tho fly.

Gestation , — About six (lays after fertilisation the female fly is capable of
depositing eggs. It is presumed that under natuial conditions the fly would
commence ovipositing as soon as this was possible and that each day such ova as
were sufficiently developed would be deposited. For laboratory rearing it was
found better to allow the female to go a couple of days longer before dissection
in order to obtain a maximum of larvae for infestations.

I Reproductive ca parti }/. — The reproductive capacity of the Amazon Fly is
considerable. Dissections undertaken to determine this showed that a total of
as many as 991 ova and larvae may be contained in a single female, and as few
as 180 ov$ and larvae. The mean capacity of 100 females wae <559.1 ova and

TOT AMAZON PLY (METAGONISTYLUM MINENSE, TOWNS.) IN BRITISH GUIANA. 63

larvae, and 188.7 ova and 368.7 larvae, with an average mating time of 17.8
minutes. Table II gives the data in this connexion.

The duration of mating does not appear to have any effect on the number
of ova and larvae produced by a female. The longest mating in the 100 females
was of 50 minutes duration and the contents of the uterus on dissection in this
instance was 310 larvae and 257 ova (total 507), while the individual with the
shortest mating, of only 7 minutes duration, contained 505 larvae and 235 ova
(total 740) ; in both instances the dissection was made on the seventh day after
mating.

Table II.

Showing Reproductive Capacity of Amazon Fly .

Month

No. of
ilies

Minutes
mating —
average

Contents of uterus — average
Larvae j Ova | Total

1983 1

December

13.9

322.1

144.2

466.3

1934

January

19.6

421.3

145.1

566 4

February

15.7

449.3

184.4

633.7

March

14.7

417.8

191-5

609.3

April

1G.1

2GG 9

227.2

494.1

May

25.0

345.0

240.0

585.0

Total

100

107.0

•> 999 1

A., «■'«.*

1,132.4

3,354.8

Mean

___

17.8

368.7

188.7

559.1

Number of parasite* per host. — In the roaring of the parasite in the
laboratory host larvae were infested with" one or two larvae according to the stage
of development and size, with a preference on the whole for single infestations,
especially when host larvae were obtained from an area in which the* fly was
already established. That this method gave satisfactory results will be seen
from the recovery figures of the laboratories given later.

As to the number of parasites that will develop within a host under natural
conditions, examinations have shown that with I), saccharafi * as the host from
60 to b5 per cent, of the larvae parasitized contain but a single parasite larvae,
from 25 to 30 per cent, contain two parasites, 6 to 7 per cent, contain three
parasites, from 1.5 to 2.5 per cent, contain four parasites, and between 0.2 and
0.3 per cent, contain five parasites. In one isolated instance in the .laboratory
one host larva was found to contain 7 parasite larvae.

Habits of adult. — The adult fly emerges under laboratory conditions
invariably in tlSte morning hours between 8.30 and 11 o’clock, but emergence

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 2.

occasionally occurs in the afternoon also, about 1 p.m. and even as late as 5.30
p.m. The emergence of the fly appears to be dependent principally on
temperature and humidity.

In the cages the adult fly will rest on cane leaves or grass placed therein
for this purpose or on the mosquito-net covering, and in so doing often assumes
a position head downwards, which may probably be considered their more
general resting position.

In the field one does not often see the adult fly and then it is usually found
resting on the underside of the cane leaves. The fly seeks this position for
shelter from the sun during the heat of the day, and during rains also it has
been observed to shelter thus. In the cooler periods during the morning and
the evening they are to be found resting on the upper surfaces of the cane leaves
and weed grasses in or near the fields.

In the cages in the laboratory the adult fly feeds readily on sugar, which
was found preferable to syrup in which they usually became entangled and died
as the result. White sugar (refined sugar or washed muscovado) proved
preferable to yellow crystals ; indeed, if fed on the latter, the mortality increased
very considerably as well as the longevity being actually reduced. This high
mortality with the use of yellow crystals was assumed to be due to the stannous
chloride used in the process of making this grade of sugar, although it was never
actually proved. Sugar of the dark crystal or muscovado grade (Java process)
proved suitable for feeding also. Under field conditions feeding of the adult
has not been observed.

As to the longevity of the fly nothing is known under natural conditions
In the laboratory flies have been kept for as long as 21 days, bub the majority
survived from 10 to 12 days. Some flies died as early as the fifth or sixth day
after emergence, which in females would be before the period of gestation
would be completed, assuming that mating took place on the day of emergence.

Host location . — In the location of the host there can be no doubt that the
fly is guided by smell. Apart from the impossibility of seeing the host located,
as it is within the cane, this has been amply proved in laboratory rearings.

At the beginning of the work when little was known of the biology of the
fly and the number of flies on hand was very few, it was not advisable, nor in
fact would the material available allow of it, to dissect flies for rearing purposes
and flies were induced to oviposit in order to obtain an approximate time when
dissections might be undertaken.

It was then found that flies with ovaries sufficiently developed would readily
oviposit on a glass plate if a Diatraea larva was squashed and smeared on the plate ;

fkE AMAZON il Y (METAGONlSfYtUM MINENSE, TOWNS.) IN BRITISH GUIANA*. 65

in fact while they could be induced to deposit by this method they took little
notice of a living Diatraea larva placed on the plate.

This method proved further that there was no selection on the part of the
adult as regards host, for they deposited just as readily in the presence of smears
of Diatraea canclla larvae as in those of 1 ). saccharalis P That the larva of the
parasite will not develop with equal facility in these hosts is another aspect that
will be dealt with later.

4. Species of Diatraea attacked.

Up to the present, Mctagonistylum has not been recorded as attacking any
genus other than Diatram and, according to Myers (11), it attacks two species,
namely, D. saccharalis , which he states is the “ favourite host/’ and from which
species the bulk of the material was obtained by him in the Amazon, and
“another Diatraea apparently a new species allied to D. impersonatdla , the most
destructive small borer in Trinidad.”

Although it was known that Mctagonistylum attacked D. saccharalis at
the time of its introduction into British Guiana, there was no information
available as to whether the parasite would attack D . canclla , the other species
commonly occurring in this country.

The small amount of material in the early consignments did not allow any
trials of this nature, and accordingly at the commencement of the work flies
were released in fields regardless of which species of Diatraea predominated.

As soon as it became possible, however, this point was investigated and a
series of infestations of larvae ef both D . sacchwalis and D. canclla were
carried out. The results of these infestations showed that, while a few larva of
D . canclla may be infested artificially with the parasite, the large majority of
fly larvae so used did not develop in this species. From a total of 6,523
Diatraea larvae artificially infested, comprising 3,503 D. saccharalis and
3,020 D . canclla , the parasite recovery was 36*0 and 1*2 per cent, respectively.
From that time D. saccharalis was used exclusively for laboratory rearings of
the fly. It should bo pointed out in this connexion that there is no actual
difficulty in infesting D. canclla larvae artificially, but the parasite larvae
invariably fail to develop beyond the second stage, apparently owing to some
physiological condition of that host.

The failure of some of the early releases of flies made in young ratoon
fields in which there was a large preponderance of D . canclla and in which
recovery of the* fly was not accomplished was also thus explained. Later, as the

AGRICULTURAL JOURNAL Of &Kim& GUiANA.

t* 1

work became better organised, when an area was being stocked with the
parasite, counts were made to ascertain the density of the Diatraea population
and the preponderant species.

More recently as the result of inquiries of sugar planters as to whether the
parasite would not eventually develop a strain that would attack 2). cauelta
more successfully, and if this desirable condition could not be arrived at by
laboratory rearing, work was undertaken in this direction.

This work has already formed the subject of a paper by the writer (5),
and it will be necessary to state here only that in rearings oxtending over a year
and comprising three separate groups of material through ten generations with
a total of 6,795 ZL cane/la larvae artificially infested, an average of less than 4
per cent, produced puparia. There was no significant difference between either
groups of larvae or generations and therefore no indication that the parasite
could be reared in numbers on this host, nor of the development of u strain of
the parasite more adapted to survival in this host species.

' 5. Colonisation of British Guiana.

Hearing the fly in the laboratory . — In the rearing oi the fly in the labora-
tory the method followed was that suggested by Thompson (18) and successfully
employed by Scaramuzza (15) and Box (2) in the rearing of Lucophayu , with
such modifications as appeared necessary for this particular insect. For
convenience a detailed account of the technique and the apparatus used will be
given.

In the first instance gravid females which are known to have mated eight
days previously are anaesthetised with carbon tetrachloride. As soon as the
fly is dead, the uterus with its contained larvae is removed in physiological salt
solution, the uterus being then ruptured and the larvae released in the salt
solution. Daitraea larvae, previously collected from the fields, are then infested
by placing upon them, by means of a small sable-hair brush, larvae ot
Metagoni sty turn . The infested Diatraea larvae are then placed in 1 oz. ointment
tins (salve tins) where they remain for some three hours and are then transferred
to young cane-shoots. The cane-shoots with the contained moth-borer larvae
are then stored in special tin-boxes for a period of twelve days. Puparia
obtained from these tins are kept for the emergence of flies, or balloon fly-traps
are attached to the tins and the flies emerging are thus secured. From these
flies a number of known mated females are retained for laboratory use, and the
remainder liberated in the fields after a period of from five to eight days, being
kept during this time in the mating cages, where further matings Occur among
tdb females not previously mated.

A modification which was adopted generally in the work here in British
Guiana -was to place Diatraea larvae directly into cane-shootsofter they were

Ikfc AilAZON fLY (METAGONISTYtUM MINENSE, TOWNS.) IN BRITISH GUIANA. 6?

infested with the parasite. This considerably shortened the work and the
recovery of parasites from such larvae was equally as good as, if not in fact better
than, with the tins.

At first large circular cages 24 inches high and 18 inches in diameter were
used for mating, but later, when it was discovered that the size of cage did not
affect mating, smaller cages were adopted and cages 18 inches high and 14
inches in diameter were used as standard. In these cages, under suitable
conditions, mating takes place readily, and they serve also to store flies until
they are liberated in the fields. These cages have four uprights and a single
cross-bar at one end by which they are suspended, and were made of i-inch
iron-rod welded at the joints. To each frame a bottom pan of galvanised iron
with sides inches high is fitted and wired into position ; the whole is
enamelled white. A cylindrical cover of mosquito net, made to fit tightly and
in the sides of which are two sleeves, is drawn over the frame and is closed by
means of tapes at the top and bottom. When flies are being kept in a cage, a
circular piece of gunny-bag (sugar bag) is placed in the bottom and this is kept
constantly damp. Two glass receptacles (Syracuse watch-glasses), one
containing sugar and the other a piece of cotton wool saturated with water, are
placed in each cage, while in addition a bowl of water in which is standing grass
(Pasjtalum vepens) may be included.

It has been found that infesting the Dint ram larvae with the parasite is
best accomplished by means of a fine sable-hair brush, and good quality water-
colour brushes of No. 1 size proved very suitable. Further, in doing this, if a
number of larvae are removed from the salt solution at one time and placed on a
black plate in a vertical line, it facilitates the work of infesting, as they may
readily be seen as they walk out of line about the black plate. By this method
assistants are usually able to work without the aid of even a low-power lens, but
for less keen eyes a circular reading glass about 3 inches in diameter mounted
in a flexible arm proved a very useful aid.

Each Diatraoa larva is wetted with a dab of salt solution before the
parasite larvae are placed on it, and what *was found to work even better was to
keep the larvae ( D. scirrhamlis) in glass tumblers and to transfer lots of 10 larvae
at a time to a potri dish containing salt solution prior to infestation, the larvae
being taken from this dish and infested immediately.

Should the Dial ram larvae be about full-grown, two parasite larvae are placed
upon them (these are referred to as “ doubles”), while if they are about third instar
or rather undersized, they are infested with only one parasite larvae (“ singles ”).
Small larvae are not infested.

If the tin method is used, a piece of blotting or filter paper wetted with salt
solution placed in each tin greatly improves the chances of survival of parasite
larvae Which tnjy drop or crawl from the host after it has been infested, and the

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

t*. 1

infestation is greatly improved by this means. A thin coating of paraffin wax
applied to the inside of each tin retards corrosion and so prolongs the useful
period of these receptacles.

In the direct shoot method the infested larvae are placed in small cane-
shoots in which a small pit has been cut previously, and as each larva is placed in
the shoot and directly infested a small rubber band is placed round it to keep it
closed. Subsequently shoots with infested larvae to a total of ten are slipped
under one band, and they are placed in such bundles in the storage tins.

The cages used for storing cane-shoots containing infested larvae are
galvanised iron cylinders (known as the “ body ”) to which are fitted tops and
bottoms, and are of two sizes, namely, 11 inches high by 10 inches diameter, and
11 inches high by 7 inches diameter. In each body about half-way between the
top and bottom edges is cut a circular hole of inches diameter around which
is soldered a rim one inch high. The tops and bottoms are made to fit tightly
inside the body so as to prevent the egress of Diatrara larvae, or when an
outside cover is fitted a bead of about i inch projection is inscribed around the
body about 1 £ inches from the top and bottom edg&s so that when the covers are
in their places their edges come in contact with the bead, so making the body
secure against the escape of the Dint rant larvae. To the circular opening in the
body is fitted a cap of mosquito wire-mesh which affords ventilation to the
cages and prevents excessive condensation of moisture within.

In storing the cane-shoots in these tins a layer of damp bagasse or sawdust
is placed in the bottom pan and the shoots with the contained larvae stood upon
this. It is essential to the production of parasite puparia that the moisture in
these tins should be regulated to prevent the drying out of the shoots or the
development of excessive moisture, which causes the formation of moulds. The
temperature in these tins is surprisingly low and constant when thus prepared
and is in the vicinity of 29-30 J C. even when there is a good deal of beat being
generated by the rotting cane-shoots; the relative humidity being in the vicinity ot
100 per cent. The storage tins are each numbered on the body, top and bottom,
from 1 to 31 and the shoots stored therein according to the date of the month on
which the contained larvae wore infested, “doubles” and “singles” being kept
separately for the purpose of working out the percentage of recovery.

After the cane-shoots have been stored thus for 12 days, balloon fly-traps
are fitted to the opening, the circular cap being first removed, and in a day or so
the flies commence to emerge. The balloon fly-traps fitted to these tins were of
local construction and measured 9 inches long by 2 \ inches in diameter with a
cone about 3 inches high, the top being made in the form of a cap which was
readily removeable to allow of the transference of the llies.

k In practice, these balloon traps were often abandoned, however, and the
puparia actually searched for by tearing apart the shoots. This was rendered
somewhat easier than may be generally imagined by the decay of the shoots*
and assistants with nimble fingers do not injure many puparia/’

THE AMAZON FLY (METAGONISTYLUM MINENSE, TOWNS.) IN BRITISH GUIANA. 69

The puparia obtained are then placed on damp bagasse or sawdust in 2 lb,
jam bottles covered with wire-gauze tops.

The method of storing in tins and securing the flies in traps, if it does not
greatly increase the number of flies obtained, certainly effects a considerable
saving in time, and on the whole is a marked improvement on tho former
practice, but for estate practico tho searching method was generally preferred.

Mated female flies kept for laboratory use are confined in 2 lb. jam bottles
from which the central area of the cover has been cut and mosquito wire-gauze
substituted. In each bottle is placed a piece of blotting paper on which there
are a few crystals of sugar. One lb. jam bottles may also be used for this
purpose and have proved entirely satisfactory. The sugar used must be either
granulated white or dark crystal (muscovado).

It was found convenient when working in small spaces, as were most of
the insectaries used ip the work, to suspend tho mating cages from the top of
the insectary, and to arrange a counterpoising weight run over a couple of pulleys
to allow the easy lowering and raising of the cages. The mating cages in the
present instance weighed approximately 10 lb. and as counterpoising weights
sash window weights or small bags filled with sand were used. Double-decked
tables are also a great saving in space.

Temperature and humidity both play an important part in the artificial
rearing of the insect (as will be observed from the statements made elsewhere
in this piper) and must be regulated as tar as possible. The methods used in
obtaining the desired temperatuies and humidities ha\e already been mentioned.
It remains only to say that in the storage tins for shoots the temperature was
much less than would be generally imagined with the decay of shoots taking
place therein, and was generally found to be about 30^C. while the humidity
was in most instances nearly 100 per cent. R.H. In the laboratory temperature
and humidity readings are taken three times a day, namely 8 a.m., 1 p.m., and
4 p.m., and there is also a self-recording thermo-hygrograpli.

Laboratories . — A laboratory was erected for the investigation on the Sugar
Experiment Station from a free grant made to tho Colony by the ^Empire
Marketing Board for the purposes of sugar-cane research. A portion of equip-
ment was also met from this grant. Later, with the actual introduction of the
Amazon fly it was found necessary to enlarge the laboratory as well as to add to
the equipment and apparatus, and this was met by funds provided by the
British Guiana Sugar Producers’ Association.

The laboratory as first erected was a small detached building 37 ft. long by
17 ft. wide, of wood framing and concrete stucco panels, .raised on concrete pillars
3 ft. high, a part of the building measuring 9 ft. by 17 ft. being screened with
brass mosquito wire-mosh for use as an insectary. In order to protect the
insectary against driving rains three small sloping glass roofs were affixed
around the exterior. Later the building was enlarged by extending the
insectary a further 10 ft,

AGRICULTURAL JOURNAL OF BRITISH GUIANA. ’

tx,a.

On the sugar estates there has been a great diversity of typo of insectaries,
as might be expected, it being very often a matter of making an existing
building serve the purpose ; thus we have worked in structures varying from
what might be considered as ideal for a field laboratory with well-made benches
and adequate apparatus, housed in a good building properly painted, to a
structure that started its life as a large dog-kennel and immediately prior to the
work was a calf-pen with a low, leaky roof and roughly put-togother benches of
undressed wood.

The size of the insectaries used throughout the work both at headquarters
and on the estates approximates 324 sq. ft., being roughly 18 ft. by 18 ft. With
three assistants working, some 200 to 300 flies per day were produced in such
laboratories, the number being regulated largely by supplies of Diatraea larvae
from the fields.

Colonisation of the Sugar Estate *. — At the time of the arrival of tlio
first consignment of the parasite nothing was known of its bionomics, and the
small number of flies (3) obtained from this shipment did not allow of any
knowledge being obtained in this respect. So that when the second consignment
arrived it was still unknown whether the insect would be amenable to laboratory
rearing.

It was decided, therefore, to make liberations directly into fields of some
of the adult flies emerging from the consignments pending the investigation
of the bionomics of the insect and the matter of laboratory rearing.
Accordingly, liberations of flies from the 3rd and 4th consignments were made
in September and October.

At that time the weather was hot and dry, as is usual at this period, and
Diatraea was generally scarce, and of those present D. canella predominated.
No recoveries from these liberations were recorded and, as mentioned elsewhere,
it is believed now that this was largely due to the preponderance of D. canella
in the fields in which the liberations were made.

Liberations of this nature were made also with flies from the 5th and 6th
consignments. During the first week in November (2nd and 9th) in a field
of plant canes at Pin. Non Pareil (NP 29) 314 flies were liberated, and on
22nd November two puparia were found in a single bored shoot from which,
on the following day, two Amazon flies emerged. Thus about three months
after the arrival of the first flies in British Guiana the first recovery of the
parasite was made.

In the meantime it was found that the technique which had been
employed in connexion with the rearing of Lixophaga was also applicable to
Metagonistylum and laboratory rearings had already been commenced.
Diatraea had been infested in the laboratory as early as 21st September from
fhes of the 2nd consignment, which arrived on 12th September and from which
tne first flies emerged on the following day, and the first laboratory reared
flies were obtained on 7th October, 1933,

THE AMAZON FLY ( MET AGON ISTYLUM MINENSE, TOWNS.) IN BRITISH GUIANA. 71

From that date regular laboratory rearings continued. For the next
eighteen months, and during the course of the work under the Colonial Devel-
opment Fund grant, flies were reared and liberated on, or breeding stock
supplied to, every sugar estate in the Colony.

Liberations having been made under suitable conditions, it was usually
but a few weeks before recovery of the parasite could be made.

At the commencement the headquarters laboratory undertook the rearing
of all flies and supplying of estates, the Diatraea larvae for use in the
laboratory being sent in by different plantations. As time went on it became
evident that if the entire sugar-growing area was to be stocked within a
reasonably short period it would be necessary to produce much greater numbers
of the fly than the facilities of the headquarters laboratory would allow.
Accordingly, the co-operation of the sugar estate authorities was sought, and
readily obtained, and arrangements were made to start rearing the insect in
field laboratories on certain of the larger plantations. Assistants for work in
these laboratories were obtained from the estates themselves with the aid of
the managers and these were trained in the technique of rearing the insects at
the headquarters laboratory. Ten such field laboratories were thus established
on estates. These laboratories, with the exception of Pin. Albion were directly
under the supervision of the writer; the laboratory at Pin. Albion was under
Mr. H. W. B. Moore, entomologist of that estate. These laboratories were
established at centres that were some distance away from headquarters and to
which it would have been difficult to send continuous supplies, or where the
area under the control of one group was large and it was more convenient to
do this. For the nearer plantations as well as the smaller ones, headquarters
laboratory supplied flies up to March 1935, when the grant terminated and the
writer went on leave.

Careful supervision was maintained over the work of these laboratories.
A weekly report on the working of each laboratory was received and frequent
visits were paid to them as appeared necessary. As to the efficiency of the
work at these field laboratories it may be stated that it was generally
satisfactory and in some instances it reached a very high standard, the recovery
of puparia having reached as high as 96 per cent, larvae infested, while the
recovery of flics reached 95 per cent, puparia.

Up to the time of the termination of the grant (March 1935) that is, at
the end of eighteen months, some 195,677 flies had been reared in all
laboratories. Of this number, 25,226 or 12.8 per cent, were produced at the
headquarters laboratory.

Since that time some 180,020 more flies have been produced on the sugar
estates, making a grand total of 379,697 flies produced in all laboratories over
the period of two years since its introduction.

The actual number of flies which were liberated was, however, considerably
less than the figures given above. As regards headquarters laboratory, a total
of 25,339 flies was reared during 1933-35 and 18,174 were distributed, that is,
71.7 per cent. In addition, some 2,000 flies were used in tjxq laboratory,

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

rx,2.

6. Cost of Introducing the Parasite.

It is difficult to state any exact figure of the cost of introducing the Amazon
fly into British Guiana owing to the conditions and arrangements under which
the work was carried out. Nevertheless, a figure, which for general purposes
may be taken as representative of the cost of the introduction of the parasite,
has been arrived at and in order to complete this record it is felt that it should
be included here.

As has been stated previously, the British Guiana Sugar Producers’
Association provided funds to the extent of £2,000 for the actual cost of the
introduction. This amount provided for the purchase of a special launch for
work on the Amazon and its transportation through British Guiana thence, the
transportation of the personnel and supplies of the expedition, the pay of such
members of the expedition as were specially engaged for the purpose, the
expenses of collecting the parasite in Brazil and its shipment to the Colony, and
the pay of the junior laboratory staff at Georgetown.

Other charges which should be included properly in the cost of the
introduction, but which were in fact not thus charged but were paid either
from Imperial, Colonial, or other funds, would be the salaries of both Dr. Myers
and the writer.

Making allowances for such charges and also for some other incidental
expenses, but not including previous ecological work done on Diatraea, the total
cost of introducing the fly into British Guiana, as distinct from the colonisation
of the estates, that is, for the work covering the period April to December 1933,
did not exceed £5,000 ($24,000).

From the material received in the Colony it has been shown that 1,400
flies were secured, and basing the cost on this number only, the cost per fly was
$17.10. In actual fact, by the end of December 1933, some 3,384 flies had been
obtained (including 1,400 in original shipments) and of these, some 2,690 flies
had been distributed to the sugar estates, and if the costs are worked on this
latter figure of 2,690 flies, the cost per fly was only $8.92 or £1 17s. 2d.

7. Parasitism of Diatraea saccharalis in Rice and other Host-plants.

The Amazon Fly has been observed to parasitize Diatraea saccharalis in
this Colony in other host-plants as well as sugar-cane. Only a few months after
its introduction the fly was recorded as parasitizing D. saccharalis in the rice
fields adjacent to the Sugar Experiment Station where the headquarters labora-
tory was situated, and later it was recorded in this host-plant in other localities
as well.

Since that time there have been observed a number of instances of
parasitism of D. saccharalis in rice. During the past year this parasitism
appears to have increased, but no data are available to confirm this.

THU AMAZON FLY (MJ3TAGONISTYLUM MINBNSE, TOWNS.) IN BRITISH GUIANA. 73

That D. saccharalis in rice should be attacked is not surprising ; in fact,
it was what was expected, for the aquatic nature of the crop offers conditions
which it seems would be favourable to the development of the fly. The
importance of this lies in the fact that rice, which is the second important crop
of the Colony, is at times seriously attacked by D. saccharalis and at all times
acts as an important alternative crop for the pest.

On sugar estates either in cane-fields or rice-fields or in their immediate
vicinity, the Amazon fly has been recorded also as attacking 1). mccliaralis in the
grass hosts Kchinochloa polystachya (IJBK), Hitch., E , crasgalli cruspavoris
(HBK), Hitch., “Bamboo Grass,” llymenachne amplcamivlia (Rudge), Ness.,
“ Bissy-bissy,” Cypcrus articulatus, L.,and Para Grass, Panicum harbinode , Prin.

8. Status in 1937.

Examinations made on sugar estates at different times after the introduc-
tion of the Amazon fly into this country showed long since that the insect had
established itself not only in sugar-cane but also in rice, and as regards the
former crop at least was parasitizing a fair proportion of the Diatraca saccharalis
in that host-plant.

A survey carried out about the middle of 1935 by Mr. F. A. Squire, while
engaged as Supernumerary Entomologist in this Department, showed further
that some two years after the introduction of the parasite and the colonisation
of the sugar estates the insect was still doing good work. The results of this
survey were not published.

About a year ago it was considered desirable to undertake another survey,
and in January 1937, the work was commenced, continuing as opportunity
allowed, to January 1938. In the survey it was not possible to carry out
examinations of all the sugar estates in the Colony, but fifteen sugar estates were
examined extending from Pin. Skeldon on the extreme east of the Colony to
Pin. Versailles and Schoon Ord on the West Bank of the Demerara River. It is
believed that the number of estates examined and the area over which they are
extended are sufficient to allow the results to be considered as being representa-
tive of the general conditions over the sugar-growing area.

As regards Pin. Albion, Berbice, the survey of that estate was carried out in
conjunction with Mr, H. W. B. Moore, entomologist of that estate, who undertook
the field collections of material.

A total of 212 fields was examined, comprising 88 plant fields, 54 first
ratoons, 56 Second ratoons and 14 third ratoons. In 155 fields (73.1 per cent.)
the Amazon fly was found parasitizing either /). aaccharalis or D . canella or both,
144 fields showing a parasitism of D. saccharalis only, but no field was found in
which only D. canella was parasitized.

In these fields a total of 37,332 “ deadhearts ” were cut out, of which 20,998
or 56,3 per cer^t. were empty. Of the remainder, 14,274 (37.9 per cent, of the

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 2.

total) contained living Diatraea , in the proportion of 6,271 or 43.9 per cent.
D. saccharalis (the black-headed borer) and 8,003 or 56.1 per cent D , canella
(the yellow-headed borer) j 2,060 or 5.5 per cent, of the 14 deadhearts ” were the
result of other causes, including white grubs (hard-back beetles) and rats.

In 5,371 D. saccharalis found in positive fields, 863 (16.0 per cent.) were
found to be parasitized by the Amazon fly at the time of examinations of the
fields, the parasitism ranging from 3.4 per cent, to 36.2 per cent. While of the
total of 212 fields, 39 (18.4 per cent.) showed parasitisms of 1). saccharalis of 30
per cent, and over. If, however, all the fields examined are included, both
positive and negative, the parasitism works out at 13.7 per cent. 1). saccharalis .

The parasitism for 7). canella , as expected, was low, 0.32 per cent, for
positive fields and 0.23 per cent, for all fields.

Records were kept during the survey as to the number of parasites per
host. Of a total of 863 Diatraea saccharalis records, it was found that 513 or
59.4 per cent, contained only a single parasite, 263 (30.5 per cent.) contained
two parasites, 66 (7.6 per cent.) contained three parasites, 17 (1.9 per cent.) four
parasites, and only 4 (0.5 per cent.) contained five parasites per host.

The puparia of the fly found in the field agreed very closely with these
figures and wore in the proportions of 59.4, 31.4, 7.5, 1.4 and 0.3 per cent, for
one, two, three, four and five parasites per host respectively.

In January 1937, Mr. H. W. B. Moore recorded a hyperparasite of the
Amazon Fly from Pin. Albion, Berbice.

This appearance of a hyperparasite was not unexpected, for it had long been
known that the native fly parasite of Diatraea > Leskio/talpax (Stomatodexia)
diadema , Wied., was attacked by the hyperparasite Sign iphora dijderophaga ,
Girault, and the possibility of this insect attacking Metagonistghnn was well
recognized at the time of the introduction of the Amazon fly. This was con-
firmed when a determination of the insect was made by Dr. C. Ferriere of the
Imperial Institute of Entomology.

In addition, Squire (16), in his report of 1935, had mentioned tho finding
of a puparium of Metagonistgluni which had apparently been attacked by a
hyperparasite, although he did not obtain any specimens of tho insect.

Accordingly, daring the survey, precautions were taken to secure hyper-
parasites in order to obtain data as to the prevalence of the insect.

On four estates of the fifteen the hyperparasite was obtained, namoly, Pins.
Port Mourant, Albion, Diamond and Farm. This would indicate that the hyper-
parasite is well distributed over the sugar area.

Of the 45 fields examined on these estates, in 13 (29 per cent.) hyperpara-
sites were found, while of 178 puparia collected, 17 (9,6 per cent,) produce4

THE AMAZON FLY (MBTAGONISTYLUM MINENSE, TOWNS.) IN BRITISH GUIANA. 75

hyperparasites. If, however, the whole Amazon fly population of these fields is
considered, namely 516 larvae and puparia, the percentage destroyed by hyper-
parasites would be only 3.3 per cent.

Commenting on the larval parasitism, Myers (11) in his review of the
Diatraea situation in British Guiana in 1031, stated that the combined parasitism
of the eight important parasites was 6.9 per cent, of the borers in cane. The
larval parasitism by the Amazon fly of 16.0 per cent. I). media rails, in the
present survey must, therefore, be considered as very satisfactory.

9. Shipments of the Parasite to the West Indies.

While perhaps not strictly within the scope of this report, in order to make
the account of the work in the Colony complete, opportunity is taken here to
make mention of shipments of the Amazon fly which have been made from
British Guiana since its establishment here.

St. Lucia . — As the result of a request from the Sugar Planters of St. Lucia*
B.W.I., to the Brittsh Guiana Sugar Producers’ Association, a shipment of
puparia of the Amazon fly was made to that island in November, 1934. The
shipment was made by tho writer direct to Mr. Harold E. Box, entomologist
engaged under the Colonial Development Fund, who was at the time stationed
in St. Lucia (3).

Two hundred and twenty puparia of the fly were despatched by air mail
from Georgetown on 27th November 1934, and anived at St. Lucia the following
day. Mr. Box subsequently reported that the puparia were received in good
condition. Bearings of the fly were undertaken and the establishment of the
insect in St. Lucia has formed the subject of a report by Mr. Box.

Puerto Rico . — In December 1935, Mr S. M. Dohanian, of the Puerto Rico
Experiment Station of the United States Department of Agriculture came to the
Colony to obtain material of the parasite for shipment to Puerto Rico. Mr.
Dohanian remained in the Colony until February 1936, during w hich period
some 6,000 adult Amazon flies were sent by him by air mail to Puerto Rico.
Consequent on the failure of the fly to establish itself in Puerto Rico, Dr. K. A.
Bartlett, also of the Puerto Rico Experiment Station, visited tho Colony in
September 1937 and made further shipments of the fly to Puerto Rico.

Trinida/L — At the request of the Director of Agriculture, Trinidad, and
with the approval of the British Guiana Sugar Producers’ Association, shipments
of the parasite totalling some 800 puparia were made to Trinidad in September
and October 1936. These shipments were made by the writer and were received
by Mr. A. H. Pickles, entomologist, Department of Agriculture, Trinidad.

More reoently, a further small consignment of flies was sent to Trinidad by
Dr, K. A, Bartlett while he was in the Colony,

AGRICULTURAL JOURNAL OF BRITISH GUIANA,

[X, 2.

10, Acknowledgments.

Any account of the work with the Amazon fly in this Colony would not be
complete without acknowledgment of the assistance which I received in one way
or another during the period.

Firstly, I would mention Dr. J. G. Myers, with whom I was associated both
in this work and for some period before, during which tho purely ecological
investigations on Diatraca were undertaken.

To the sugar planters of the Colony also I would tender my thanks for their
ready and active help which was largely responsible for the success which
attended both the Dtal mm ecological work and the subsequent colonization of
the sugar estates with the Amazon fly, and especially to Messrs. J. C. Gibson,
G. E. Anderson, G. M. Eccles, W. H. Richards, D. Mowatt and R. B. Hunter.

Finally, I have to thank my laboratory assistants at headquarters laboratory
as well as those on the sugar estates who readily put in extra time in order to
make the work a success.

References. 1

1. Aldrich, ,J. M. (1933). Two reared species of Tachinids from South

America. — Proc. Biol. Soc. Wash, 3 5, pp. 170-173, 1 fig.

2. Box, II. E. (1933.) Outline of work in Antigua and St. Kitts during the

year 1932. — Report on the introduction and establishment of the Cuban
parasite, Ltrophaga diatraea Townsend. Antigua, p. 40.

3. . (1933;. Further observations on Sugar-Cane moth borers ( Diatraca

spp.) in St. Lucia. Introduction of tho Cuban Parasite Lurophaga diatraea
Townsend. Report upon a visit to St. Lucia, August- September 1933,
with an Appendix on the recommended biological Control of the White
Coffee-leaf Miner ( Leucoptera coffeella $ Guer.) in St. Lucia. — 10 pp.
7 refs. Castries.

4. Cleare, L. D. (1931). Sugar-Cane moth-borer investigations in British

Guiana: the present position. — Agric. J. Brit. Guiana. 5, pp. 13-21.

5. . (1937). Experimental rearings of the Amazon fly Metagonistglum)

minrme Towns.) on the yellow-headed sugar-cane moth-borer {Diatraea
canetla Hmpsn.), — Agric. J. Brit. Guiana, 8, pp. 190-194.

6. . (1938.) Status of the Amazon fly in British Guiana, 1937. — Agric. J.

Brit. Guiana, 9, pp. 12-24.

7. Dohanian, S. M. (1937). Tho introduction of parasites of the sugar-cane

borer into Puerto Rico. — J. Agric. Univ. Puerto Rico, 21, op. 237-241.

8. ^Dohanian, S. M. (1937). The search in the American tropics for bene-

ficial insects for introduction into Puerto Rico. — Agric. Notes P. Rico
Exp. Sta, Mayaguez, P.R. no, 76, 7 pp. <

fkE AMAZON PLY (MBTAGONKTYLUM MINENSE, TOWNS.) IN BRITISH GUIANA. 77

9. Haul and, 8. G. (1937). A note on two larval parasites of the sugar-cane
moth-borer, in Sao Paulo, Brasil. — Trop. Agric. 14, p. 280.

10. Month, 0. (1933). Um novo parasita da broca da cana ( Dinlraea

saccharalis F.) e consideragoes sobro esta broca. — Bol. Agric. Zootec. Yet.,
6, pp. 559-563, 3 figs.

11. Myers, J. G. (1931). Preliminary report on an investigation into the

biological control of West Indian insect pests. — E.M.B., 42 , 173 pp. 2
maps. H.M.S.O. London.

12. . (1931). The discovery and introduction of the Amazon fly — a new

parasite of cane-borers (Diatraea spp.). — Trop. Agric., 11, pp. 191-195.

13. — — . (1935). Second report on an investigation into the biological control

of West Indian insect pests Bull. Ent. Res., 26, pp. 181-252. 1 map,

1 1. . (1936). Biological control of sugar-cane pests in the British West

Indies and British Guiana. — Proc. Iut. Soc. Sugar-Cane Techn. 5,
Brisbane, 1935, pp. 381-385.

15. Scaramttzza, L. C. (1930). Preliminary report on a study of the biology

of Lixnjthaga dinlraea, Tns. — J. Ecod. Ent., 23, pp. 999-1004.

16. . (1933). Observations on certain Dial rat a parasites of Brazil and

British Guiana. — Proc. 7th Ann. Conf. Asoc. Tecnieos Azucareros de
Cuba, pp. 60-64.

17. SQUIRE, F. A. (1935). Progress roport on the present status of the Amazon

fly in British Guiana. (Unpublished Rep., Col. Devpmt. Fund.)

18. Thompson, W. R. (1930). The biological control of insect and plant pests.

— E.M.B.. 29 , 124 pp. H.M.S.O., London.

19. Townsend, C. H. T. (1927). Synopse dos gencros muscoideos de regiao,

humida tropical da America, com generos e especies novas. — Rev. Mus.
Paulista, 1 5, pp. 205-385, 4 pis.

TESTING LARGE NUMBERS OF RICE VARIETIES BY
THE QUASI-FACTORIAL METHOD.

P. A. CHAN-CHOONG, B.sc., A I.O.T.A.

Assistant Plant Breeder, Department of Agriculture.

Introduction.

The plant breeder usually has to handle large numbers of varieties and
strains and his function consists largely in selecting promising, and discarding
unpromising, material from that at his disposal. He must therefore have some
means of testing which will enable him to assess the capabilities of such large
numbers quickly and precisely.

Replicated variety trials, in the form of randomised blocks or Latin squares,
offer an efficient means of comparing the few superior varieties which emerge
from the bulk of the plant breeding material ; but the initial processes of sifting
and discarding involve the testing of too large a number to be satisfactorily
handled in this way. As Yates points out “a Latin square containing the whole
of the varieties is impossible, being both too unwieldy and requiring too many
replications, and even randomised blocks containing the whole of the varieties are
unsatisfactory, for the blocks are likely to contain too many plots to eliminate
fertility differences efficiently.”

Yates however has recently developed a new technique for testing large
numbers. He calls it the Pseudo-factorial (Quasi-factorial in a more recent
publication) arrangement and the Incomplete Randomised Block method.

At the Rice Experiment Station, British Guiana, it has been the custom to
base the preliminary judgment of a variety on its average performance in progeny
rows, over a number of seasons, as oompared with the progeny row yields of the
standard varieties, each variety being planted in a progeny row plot consisting
of 10 rows, each 1 foot apart, with 114 plants per row also spaced 1 foot apart.
Progeny rows are admirable for acclimatising exotic, and purifying impure, varie-
ties and they serve a very useful purpose os small observation plots, but their
yield figures can give only a rough idea of varietal yielding power, since owing to
lack of replication, no estimate of the error due to soil heterogeneity, etc., can be
made. Some effort may be made to remove soil variability by using systemati-
cally placed controls or checks, but Yates has demonstrated that this is not likely
to prove more efficient than the quasi-factorial arrangement. The quaBi-factorial
arrangement was tried here for the first time in 1938 and proved so useful that it
was thought that a description of the experiment and results might be of interest
to other workers in this field.

tfflsfriNG OP BICE) VARIETIES BY THE) QUASI-FACTOBUL METlIOt). 79

Method.

With numbers above 100 and up to 200, the quasi-factorial method with two
or three groups of sets seems to be the most useful, since the large number of
replications required in the incomplete randomised block method is hardly possi-
ble on account.of many reasons, economic chiefly. In view of the fact that in the
method with two groups of sets, too great a discrepancy may occur between
estimates of error variance for comparing varieties in the same and in different
sots, it was thought advisable to use the method with three groups of sets.

169 varieties were tested, of which 70 were old selections made before 1937,
41 were new selections made in 1937, 27 were hybrids bred at the station, and 31
were imported foreign varieties.

With the varieties in each set (p) = 13, the total number of varieties tested
was 169 ( — p ’). These are arranged in a square, the varieties being designated
by numbers u v w> using the first figure u to represent the rows, the second v to
represent columns, and the third figure w being written in along the diagonals.
The following square is obtained

Ill 1 2.13 1 3.12 1.11.4 1.12.3 1.13.2

2 1 2 2 21 2 3.13 2.11.5 2.12.4 2.13.3

3 1 3 3 22 3 31 3.11.6 3.12.5 3.13.4

11.1.11 11.2.10 11.3.9 11.11.1 11.12.13 11.13.12

12.1.12 12.2.11 12.3.10 12.11.2 12.12.1 12.13.13

13.1.13 13.2.12 13.3.11 13.11.3 13.12.2 13.13.1

Three groups X, Y, Z are then written out as follows :

Group X : as above

Group Y : obtained from Group X by writing in rows for columns, and
colums for rows, thus :

111 212 313 11.1.11 12.1.12 13 1.13

1 2.13 2 2 1 3 2 2 11.2.10 12-2.11 13.2.12

1 3.12 2 3.13 33 1 11.3.9 12.3.10 13.3.11

1.11.4 2.11.5 3.11.6

1.12.3 2.12.4 3.12.5

1.13.2 2.13,3* 3.13.4

11.11.1 12.11.2 13.11.3

11,12.13 12.12.1 13.12.2

11.13.12 12.13,13 13.13.1

go AGRICULTURAL JOURNAL OF BRITISH GUIANA. L3* &•

Group Z : obtained from Group X by writing in the diagonals along the
rows, thus :

111 221 331 11.11.1 12.12.1 13.13.1

212 322 432 12.11.2 13.12.2 1.13.2 *

313 423 533 . . 13.11.3 1.12.3 2.13 3

11.1.11 12.2.11 13.3.11

12.1.12 13.2.13 1 3.12

13.1.13 1 2.13 2 3.13

8.11.11 9.12.11 10.13.11

9.1112 10.12.12 11.13.12

10.11.13 11.12.13 12.13.13

Statistical Calculations.

Total number of sets = 3p = 39.

Each group is replicated twice, so that <

Replications of each group

(n) - 2

Complete replications

(r) = 3n =

Total number of blocks

(b) = Sup =

Total number of plots

(N) — Sup* =

1014

Each plot consists of two rows of plants 1 foot apart, spaoed 1 foot apart
within the rows. Each row contains 34 plants. The sets were not arranged at
random within each group, but the varieties were randomised within each block.
The groups were laid down at random on the field. All yields are given in
ounces. There were three groups X t , Y,, Z t , each with its replication X», Y 3 ,
Z,.

The first step in the computations is to set out the yields of the individual
plots as in Table I, where the yields of the first replication of the first group (Xi)
are shown with the marginal block totals. To save space only a few sets are
shown. These yields are then summed for each group : this is shown also in
Table I for the group X where the figures represent the totals of the yields in
Xi and Xj, and the marginal totals Xu . . and X.v. are collected according to set.
It is now easy to tabulate the variety totals Tuvw as shown ; this is done in two
ways so as to give the marginal totals Tu . . , T.v. and T . . w which are required
in the next step.

The next step is to prepare a table of the quantities Cu.., C.v. and C..w.
These are correction terms based on the yields of the other varieties in the same
set and values are obtained for every set in each group, these values being given

Tu. . - 3Xu.. , T.v. - 3Y.v.

T. .w - 3Z..w

. Application

of these correction terms to the actual means of the variety totals will result in

the corrected mean yields shown at the bottom of Table I. Qa. . and C.v. are

Table I.

Varieties after Randomisation and Corresponding Plot Yields in Groug A’

Testing op rice varieties by the quasi-factoRIal method. 81

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AGRICULTURAL JOURNAL OP BRITISH GUIANA,

> » £r

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(1.132)

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(2 13.3)
60 488

(1.12.3) 1
69.769

(1.11.4)

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86.069

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TESTING OP RICE VARIETIES BY THE QtTASI-PACTORIAJ, METHOD. 83

in the corresponding row and column of the table, but C . . w has to be picked
out from the value w for the variety. Thus,

12.13=

477.50 ■
' G

1.630 - 2.742 + 2.744 = 77.955.

For the analysis of variance the sums of squares are required for total, blocks
and varieties. The first two are calculated in the usual way. The sum of
squares of varietes is calculated according to the following scheme :

2 (Tuvw »)/ 3n

= 6,585,602.0729

2 (3Xu . .— Tu

. y/Cmp )

2 (3Y ,

.v.-T.

v.) 2 / 6np

= 18,380.4960

2 (3Z .

.w-T.

,w) 2 /Gup J

—

(3X

. . .— T .

. yi l.Snp'J

—

(3Y

. ..-T.

. .) 2 /l8np 2

) = - 639.8521

—

(3Z

...-T.

. yiiSap^

—

2 (Xu

. . 2 )/np

)

—

2 (Y.

v. J )/np

= -6,451,900.7152

—

2 (Z . .

w a )/np

(varieties)

—

s.s.

= 151,441.9716

In this scheme the sum of squares for (groups + sets + varieties + mean)
is given by

S(Tuvw-) + 2 (3 Xn . Tu . .)~ + X (3Y . v T . v .)-* + >: (3 Z . . w-T. . w) 2
3n Gnp

~ (3? - T. ..) 2 + (3Y.. . — T . . +_(3Z . . T . . .Y

18np’ J

and the sum of squares for (groups 4- sets + mean) is determined from
2 (Xu . ,~ ) + 2(Y.v. J ) T 2 (%. .w 2 ). The difference gives the sum of squares
np

for varieties.

The analysis of variance now reads as follows :

S.S.

^ D.F.

Vaiiance

i log

' Calc,
value of Z

Blooks

93,713.9786

Varieties

151,441.9716

168

901.4 103

3.4020

1.3620

Error ,

i 56,935.8697

768

72.0519

2.1400

Total

301,091.8199

1013

•

The reqaired observed values of Z at the 5 per cent, and 1 per cent, points
do not exceed ,2654 and .3746, indicating that varietal differences are significant.

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

tX 2.

Iu making comparisons the varieties may be classified according to whether
they occur or do not occur in the same set, />., differing in two sets or three sets.

If s® is the error variance, the variance of the difference between the means
of varieties occuring in the same set is

V (tuvw — tuy/wO — 2i ?'•* /I + _1_\ — 25.8(5

3n V P/

S.E. = •/ 25.8(5 = 5.085
and for varieties not occuring in the same set,

V (tuvw — Wy/yy/) = 2s 8 /I + _3_\ = 2(5.78

v 2 P ;

S.E. =^2(5.78 =5.175
The average variance of all comparisons is

Ym = 2s 1 / p + 3i \ = 2(5.59 S.E. = v^cT.W = 5.15(5
3n VP + 1 /

Results.

The differences between the error variances are not great, and for general
purposes of comparison the average variance may be used. Twice its standard
error may be taken as a significant difference. Table II gives the list of the 169
varieties with their corrected mean yields arranged in order of descending
magnitude and in groups of equality based on the significant difference of
10.312 ounces. Thus D 162 is significantly inferior to the varieties in group (1),
and significantly superior to the remaining varieties except those in its own
group (2). The significant difference represents 13.1 per cent, of the general
mean yield.

There were two Demerara Creole selections, of which the better gave a yield
of 81,153 ounces. Taking this as a standard of comparison, 83 varieties gave
higher yields, of which 21 are significantly superior and 85 varieties gave lower
yields, of which 27 are significantly inferior.

Greater interest centres in the 21 superior varieties. These comprise 13 local
selections (9 prior to, and 4 made in, 1937), 4 imported varieties and 4 hybrids.
Except for the 4 selections made in 1937, these varieties had been under progeny
row test for three to six seasons, and had, with the exception of one, given
superior average yields to Demerara Creole.

Of the 27 inferior varieties, 24 had given inferior average yields to Demerara
Creole over three or more seasons, the other three had given yields about equal
to this standard. With regard to the remaining varieties there has been the
same general trend to follow the results of progeny row test over the last three
or more seasons.

It would appear that one replicated experiment along the lines of the quasi*
factorial arrangement has served to confirm the results of three or more seasons
ofLproffeny row testing. But further, this experiment has shown where varietal
differences become significant and has pointed towards a few select varieties out
of the great bulk, the behaviour of which can be followed up in additional
testing.

TESTING OF RICE VARIETIES BY THE QUASI-FACTORIAL METHOD. 85

Table II.

Corrected Mean Yields in ounces per plot of Varieties in Groups based on

Significant Difference.

(/) 108.830 — 98.524

D99 (1)

108.836

71—37

105.870

D250

101.190

D99 (2)

100.086

(2) 98.310—88.004

D162

98.316

Karimganj (1) ...

07.781

1)256

07.350

D257

96.863

Minalabon

96.822

Karimganj (2)...

06.568

3—37

05.050

1)222

94.76 L

D254

04.736

54—37

01479

23—37

94.387

15—37

04.084

1)238

03.514

20—37

93.213

D103

02.078

50—37

01.000

52—37

01.406

38—37

01.112

1)255

00.023

39—37

00.887

SN3

00.864

18—37

00.427

A K Kulu

00.370

A 16.34

80.700 ■

70—37

80.615

16—37

89.455

56—37

89.308

D253

89.354

67—37

89.050

D258

88.962

5)1—37

88.721

55—37

88.483

D114

88.324

McK. Large (1)

88.227

42—37

88.009

( 3 ) 87.754—77.442

Kalyaman (1) ...

87.754

63—37

87.644

19-37

87,327

D110(l)

1)183

r>i — 37

14—37

D80

17—37

57—37

DUO (2)

43—37

SN7

Kalyaman (2)
D11G (2)

SN8
28—37
37—37
21—37
D07 15
McK. Small
SN 5
D247

40— 37
1)07 A
30 -37
0 14.31
D02

41— 37
G5 — 37
Lead Rice
D205

McK. Large (2
No. 70 (1)
08—37
Ramcajara (1
D100 (l)

DUG (1)

D88
D250
G9 — 37
58—37
8-37
D221 (2)

D297
D.C. (2)

D244

34—37

13-37

87.147
86.971
86.787
86.733
86.495
86.153
86.078
86.069
86.038
85.062
85.550
85.492
85.439
85.196
85.145
85.122
84.822
84.686
84.566
84.326
84.326
84.167
84.000
83.031
83.869
83.633
83.348
83.052
83.048
82.577
82.272
82.047
- 81.896
81.873
81.830
81.753
81.660
81.584
81.381
81.344
81.266
81.257
81.153
81.141
81.050
80.759

86 AGRICULTURAL JOURNAL OP BRITISH GUIANA, [X, 2

Table II.— {Continued.)

Corrected Mean Yields in ounces per plot of Varieties in Groups bases on

Significant

No. 79 (2)

80.662

Ramcajara (2)

80.587

D108

79.702

D91 (2)

79.341

D94

79.166

61—37

79.142

66—37

79.006

D224

78.817

No. 76 (2)

78.763

32—37

78.461

Bamboo Rice

78.165

D135

78.059

B.S. (1)

77.955

26—37

77.774

44—37

77.766

D100

77.582

12-37

77.471

{4)

77.347-

-67.035

D243

77.347

60—37

76.622

59—37

76.596

29—37

76.353

62—37

76.159

N. Patna

76.040

1)90

75.998

35—37

75.887

D246

75.816

SN 4

75.521

75.354

1)225 (1)

75.302

47—37

75.073

64—37

74.385

74.281

D91(l)

74.154

D.C. (1)

73.977

D245

73.962

45—37

73.946

D242

73.862

31—37

73.612

Bommadeva

73.599

9—37 (2)

73.173

D%60

73.160

Difference.

D225 (2)

73.114

No. 75(1)

73.050

25-37

72.909

Unity

72.716

SN2

71.964

P. Berbice

71.923

5—37 (2)

71.773

D221 (1)

71.349

33—37

71.312

46—37

71.121

D156

71.046

D188

70.886

D109 (2)

70.476

36-37

70.361

49—37 ,

70.261

B.S. (2)

70.205

D239

69.841

24—37

(59.793

No. 75 (2)

69.7(59

48—37

68.816

27—37

68.303

(-5)

D184

66 906-

— o 5.5 9 3

65.905

9-37 (1)

64.793

SN 1

64.232

1)251

(53.785

4—37 (2)

t • •

63.765

D228

• M

63.443

No. 76(1)

• t •

63.302

4—37 (1)

61 685

D 95 (1)

60.488

D266

• • •

60.063

5-37(1)

• • •

59.337

(«)

D236

58 947 and below .

58.947

Kao Bang Pra ...

48.925

D150

• • •

48.253

D261

• • •

43.027

D264

• • •

40.554

D263

37.144

D262

• • m

36.834

D267

5.767

TESTING OF RICE VARIETIES BY TIIE QUASI-FACTORIAL METHOD. 87

Discussion.

Ia all experimental work, whenever a new method is to be tried out, the
question is certain to be asked — “ Is the new method more efficient ?”, and
furthermore, if additional labour and computation are required, “Is the gain
in efficiency large enough to compensate ?” In the introduction it was stated
that the method used to gauge the yielding power of varieties was by use of
progeny rows, where no significant differences in yields can be estimated. The
quasi-factorial method is designed to measure varietal differences statistically
and because of this may be considered more ellicient, although there is no gain-
saying the value of progeny rows as observation plots.

However, the planting of 2-row plots in four or six groups as opposed to the
progeny row planting of a single 10-row plot will usually involve more labour in
planting and reaping. The last crop (quasi-factorial method) and the one before
(progeny row planting) were approximately of the tame magnitude, eo that costs
may be reasonably compared. Expenses for planting and reaping showed an
increase of roughly about $11 per acre. There is also extra labour involved in
the statistical calculations but not enough to offer any serious obstacle.

In considering the merits of the two systems, both the financial and time
factors must be considered. The former system of progen > row planting meant
that varieties had to be kept under observation for three or more seasons before
some idea of thoir capabilities could be obtained. Even then, because of the
absence of a satisfactory lay-out, the judgment was not sufficiently precise and a
largo number of varieties had, for safety, to be included in the replicated variety
trials. On the other hand, one or two quasi-factorial trials will suffice for the
selection of the really good varieties. This saving in time will more than offset
the extra cost of the quasi-factorial trials and, in addition there will be a saving
in the variety trials proper since fewer varieties will reach this stage.

The general conclusion may be reached that while progeny rows are very
useful for acclimatising exotic, and purifying impure, varieties, the quasi-factorial
method offers a more rapid and reliable means of testing a large number of
varieties, and serves as a valuable preliminary to the full variety trials with their
few select varieties.

Summary and Conclusions.

1. Attention is drawn to Yates’ quasi-factorial layout as filling the need of
the rice breeder for a method which will facilitate the early discards and selections
among a large number of strains.

2. An experiment where the method was used for testing 169 varieties is
described, and it is shown that differences of 13 per cent, in yield can be meas-
ured, It is further shown that the results of the experiment are in good agree-
ment with the average data from three seasons’ tests in progeny rows,

3. The merits of the quasi-factorial layout, in comparison with accumulating
data from progeny row plots are discussed and it is pointed out that although the
former involv& 14 per cent, increase in field costs and more statistical com put a-

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 2.

tion, it proves cheaper in the long rnn since a variety can be judged more quickly
and it is possible to reduce, to a minimum, the number of varieties to be dealt
with in the replicated variety trials.

Acknowledgments.

Thanks are due to Mr, C. H. B. Williams, Sugar Agronomist and Plant
Breeder, for his suggestions regarding this experiment and the presentation of
its results, and to F. 0. Ramotar of the Rice Experiment Station for his assistance
in the conduct of the experiment.

References.

1. Yates, F. A new method of arranging variety trials involving a large

number of varieties. Jour. Agrio. Science, 2G : 424455. 193G.

2. The design and analysis of factorial experiments. Imperial

Bureau of Soil Science, Technical Communication No. 35.

3. Goulden, C. II. Modern methods for testing a , large number of varieties.

Dominion of Canada Dept, of Agriculture, Publication 575,
, Technical Bull. 9. 1937.

DOUBLE VERSUS SINGLE PLANTING OF SUGAR CANE.

C. HOLMAN B. WILLIAMS, M A., A I C T.A . Dip Agr.,

Sugar Agronowist and Plant Breeder ,

\xr>

L. A. FORTE,

Field Assistant , Sugar Experimeni Station .

The opinions of British Guiana planters vary considerably as to the
amount of planting: material to be used in a row and its ideal disposition (single
line, staggered, double line, etc.), and the feeling is strongly held by some
that single planting produces less but bigger stalks whose size more than
counter-balances the weight of the larger number of thinner stalks obtained
from double planting. The thicker stalks, it is often claimed, are a better
commercial proposition, being cheaper to cut and load.

To throw some light on the problem an experiment was started at the
Sugar Experiment Station (Sophia) and the present paper gives the results
secured from the plant canes and first ratoons. It is thus an extension of the
report on the plant cane results made to the Sixth Congress of the Inter-
national Society of Sugar Cane Technologists.

The Experiment.

Twenty-one pairs of plots were planted to P.O.J.2878, seven pairs in each
of three different fields. It was felt that by spreading the test over three
fields, planted and harvested on different dates, more confidence could be placed
in the general applicability of any conclusions drawn. Each plot consisted of
six rows and comprised an area of 0.02548 acre. One plot of each pair was
planted double-row with twice the number of cuttings used to plant its mate
single-row. In the single planting 36 cuttings were used to a row. The aver-
age weight of a cutting was 0.48 lb., its average length 15.3 inches. At these
rates it may be assumed that single planting would involve just under two and
double planting a little under four tons of material per acre, the excess required
by double planting under the conditions of this test being 1.82 tons per acre.
The plots of each pair were contiguous along the same bed but the order of the
two plots in each pair was determined by chance. The significance of the
differences obtained was tested by Fisher’s modification of Student's method
for comparing pairs of observations.

The' numbers of the fields and the dates on which they were planted and
harvested are listed below : —

Field . Planted . Harvested. Age at Har - Harvested. Age at Har-
vest , Months . vest, Months .

15 East 19.12.36 3.3.38 14.50 27.4.39 13.75

13 East 23. 1.37 26.2.38 13.00 28.2.39 12.00

13 West £5. 2.37 9.3.38 12.50 26.4.39 13.50

AGRICULTURAL JOOIttAL OF BRITISH GUIANA.

tX,2.

Rains were abnormally high during the wet seasons and unusually low
during the dry seasons in which these canes were growing as plants (see
Table I) and the unusual weather conditions appear to have depressed the yields.
The first ratoon yields were also adversely affected by six months of contin*
uous heavy rains following the harvest of the plant canes.

Table I.

Rainfall at Sophia Sugar Experiment Station.

Month.

Rainfall,

1936—39,

Inches.

Average Rainfall,
1921 — 38,
Inches.

Excess or
Deficit during
Growth of the
Experiments.

December 193G

23.04

14.17

8.87

January 1937

14 03

9.18

5.45

February

0.75

4.27

- 3.52

March

1.53

4.78

- 3.25

April

5.19

5,4(5

- 0.27

May

13.09

11.77

1.32

June

19.95

14.37

5.58

July

19.70

11.26

8.44

August

8.23

8.54

- 0.31

September

2.(51

2.(58

- 0.07

October

4.57

3 95

0.62

November ...

3.(50

5.(53

- 2.03

December

12.7(5

, 14.17

- 1.41

January 1938

13.72

9.18

454

February

14.20

4.27

9.93

March

14.7(5

4.78

9.98

April

8.94

5.46

3.48

May

11.14

| 11.77

- 0.63

June

12.99

14.37 |

-1.38

July

12.86

| 11.26

1.60

August

15.92

, 8.54

7.38

September

2.42

1 2.68

- 0.26

October ... ....

3.37

3.95

1 - 0.58

November . .

5.29

| 5.(53

1 - 0.34

December ...

7.71

! 14.17

- 6.46

January 1939

12.25

918

3.07

February

4.11

4.27

-0.16

March

4.78

—

April ... ...

;

8.74

5.46

3.28

The topsoils of these fields are acid silts overlying alkaline silt subsoils.
The topsoils are rather low in organic matter while in the subsoils the carbon:
nitrogen ratios of the organic matter are wide.

For the plant canes, five weeks after planting, a plot by plot check was
made o£ the number of shoots (denoted arbitrarily first ordlr shoots) and

DOUBLE VERSUS SINGLE PLANTING OF SUGAR CANE.

each was labelled with a metal tag. Five weeks later another check was made
and all new shoots (denoted arbitrarily second order shoots) were labelled with
a differently shaped tag. At harvest only millable stalks were considered and
it was determined how many out of the total for each plot were 4 first order
how many 4 second order and how many were 4 late shoots as all shoots
developing after ten weeks were arbitrarily called.

Each group of stalks in each plot was weighed separately and, since the
number of stalks present was known, it was possible to calculate the average
weight per stalk. Further, from each group of stalks in each plot, fourteen
average canes were measured and sent in as a sample to be passed through a
power-driven experimental mill for purposes of analysis.

For the first ratoons, only the weight of cane and number of stalks were
determined, and a sample from each plot crushed for analysis. Consequently
none of the data recorded in Table III is available for the first ratoons.

Results and Discussion.

Stalk PopvVation.

Table II shows, for single and double planting separately, the number of
first and second order shoots at the start of the experiment and the number of
these present as millable stalks at harvest; also the number of late shoots
present at harvest. The differences in favour of double planting are also
recorded and marked with an asterisk when statistically significant.

At all stages, in the plants, the double planting gave a greater number of
stalks than the single. There was a considerable mortality among the early
shoots and, as shown more clearly in Table III, it was heavier in the double
planting than in the single but not sufficiently so to offset the much higher
population of the double-planted area. It may be said that the higher mortal-
ity used up just less than half of the initial advantage of the double-planted -
plots.

In the first ratoons the comparison was made only on millable stalks at
harvest. Here again the double planting proved superior.

AGRICULTURAL JOURNAL OF BRITISH GUIANA,

[X,2.

Table II.

Comparison oftho Number qf Stalks per Acre Produced from Single and Double

Plantings.

Young Shoots

Mill a blr Cane at Reaping

First order
(alter 5 weeks)

Reoond order
(after 10 week*)

First order

Second order

Late

Total

Singlt i
PUnt- 1
ing j

Doublf

1 Plant
| mg

1 SmgU
Plant
mg

Double

Plant-

ing

Single

Plant

ing

Double!
Plant
ID(t |

Single

Plant

ing

Doublt

Plant

ing

Single
Plant
mg {

Double

Plant

ing

Single

Plant

Double

1 llant
mg

No ( f Shoot*

Plants
l^t Ha toons

7.417

14,710

11,178

17, '90

2.888

4,717

1.787

4,70-1

17,717

16,543

22 020 |
21,877

27 840
24,278

Difference m
f a\ our oi Double
Planting

Plants •

1st H itoons

7 bn*

f 412*

1 647*

1177*

908*

3 820*

2 401*

% Increase of

Double on Single
Planting I

Plants

1st Ratoons

%04

r >7

56 06

12 81

C 12

nr,

1097

•Difference Significant.

Table III shows what percentage of first and second order plant cane shoots
lived through to harvest and the numerical composition of the crop in terms of
various orders.

Table III.

Fate of First and Seiond Order Shoots and Numerical Composition of crop by

Shoots of Di fferent O* ders.

Treatment.

% First Order Shoots
| present at

% Second Order Shoots
present at

% Composition of
Harvest.

:> weeks.

Harvest

10 weeks. ^ Harvest.

| First
order

1 shoots.

Second

order

shoots.

Single Planting
Doable „

100.00

38 93
31.18

100.00 32.14

100.00 ! 27.08

1311

17.54

16.29

18.44

70 60
64.02

* It will be seen that about two-thirds of the first order and a like portion
oi the second order shoots disappeared before the cane was harvested and that
mortality was higher when planting was double than when it was single. The
differences in this respect are statistically significant. On the ether hand, the

fcObfeLE VERSUS SINGLE PLANTING OF SUGAR CAN& 9)}

ftrst and second order shoots formed 36 per cent, of the final crop in the case
of the double planting against under 30 per cent, for the single planting.

The population appears to have been about normal for P.O.J. 2878 in this
Colony, comparing favourably with other counts made at various times and
places. This is brought out in Table IV below, where counts for the two other
standard canes are included for comparison.

Table IV.

Number oj Stalks per Acre at or near Harvest in British Ouiana .

Variety.

This

Investi-

gation.

P.O.J. 2878

Plants 23,930

1st Ratoons 23,077

Diamond 10
D. 625

vemr,

1937.

15,304

, 1

Rose Hail,

1 1937.

Port

Mourant,

1937.

o .. (1)

Sophia,
(Cooper, .
1937). 1

(2;

Various

Sites

(Clearo,

1938),

(3)

Rose Hall,
( Falconer,
1938),

23,716

26,264

*20,1577

23,800

1 !!!

17,271 !
10,K23 |

17,552

13,785

(1) Agric. Jnl , of British Guiana , VIII, No. 1, pp. 4 — 40.

(2) „ „ „ „ „ VIII, „ 2, ,,63-83,

(3) Private Communication.

Weight Composition of Crop .

The weight composition of the crop, in terms of various types of stalks, is
shown in Table V.

Table V.

Percentage Composition of Crop by Weight in Relation to Shoots of Different

Orders .

First Order Second Order Late Shoots Total

Single Double Single Double Single Double
Planting. Planting. Planting. Planting Plant ; ng. Planting.

Single | Double
Planting. , Planting.

Weight of Cane
per Aero, Tons.
Plants

1st Ratoons.

' 2.63

4,15

3 6G ,

4.78

17.20

> 17.61

23.49

17.33

26.54

19.41

% of Total, Plants :

' 11.20

15.64

15 UK

18.0!

* 73.22

60.35

100.00

100,00

Double planting gave a total tonnage of cane 12.98 per cent, higher than
single planting in the plants, and 12.00 per cent* higher in the first ratoons;
in both instances the increment was statistically significant. In the plants, as

94 AGRICULTURAL JOURNAL OP BRITISH GUIANA. [X, 2.

might have been expected, the increment was secured mainly in the first five
weeks of growth and, to a lesser extent, in the second five weeks. The highev
mortality in the double-planted plots was not sufficient to offset the markedi
superiority of these plots in number of stalks per acre. The tonnage of late
stalks was practically identical for the two types of planting, although, in thi»
category, the double planting averaged 998 stalks per acre more (see Table II)
than the single.

In Table VI certain other effects of the two types of planting are com-
pared.

Table VI.

Comparison of the Effects of Single and Double Planting on the Purity , Sucrose
in Cane %, Glucose Ratio and Length and Weight per Stalk.

First Order Shoots

Second Order Shoots

Late Shoots

Single

Double

Differ-

Single

Double

Differ-

Single

Double

Differ-

Planting

ence

Planting Planting

ence

Planting

ence

Purity

Plants :

85. G

86.3

-i

86.3

8(1.1

85.2

85.5

— .3

1st Ratoon* :

90.(5 **

90.9”

— .3**

Sucrose iu Oimic %

.11

13 66

1 3.75

— .19

.Plants :

13.45

13.47

— .02

13 76

13.65

1st Ratoons :

15 Cl**

15.92”

-.28”

Glucose Ratio,

6.43

-.31

7 54

-.<52

Plants :

G68

6.28

.40

6.12

<5.92

1st Ratoons :

» __

5.78**

5 29”

.49**

Length per Stalk, ins.
Plants :

i 73

-3

~4*

Weight per Stalk, lb.
Plants :

1st Ratoons :

i 2.10

2 04

.06

! .

2.31

—

2.57

1.77”

2.45

1 .79**

.12

—.02**

It will be seen that in neither crop had the single and double planting any
statistically significant differential effects on the juice purity, the sucrose
content of the cane, the glucose ratio or the weight per stalk. In the case of'
length per stalk of the plant canes, the double planting tended to produce longer
first and second order stalks, and in the late stalks the difference in favour of
double planting was statistically significant.

Summary.

A comparison of single versus double planting was made with P.O.J.2878
on acid silt overlying alkaline silt subsoil on the low-lying coastal belt of British
Guiana. It was found that:

1. In plant canes, double planting produced significantly more shoots per
acre in the first five weeks and the second five weeks;

“•Difference Significant.

••The stalks of the first ratoon population were not separated as regards order of appearance.

The data presented under ' late shoots ' for this crop are for all nullable qjjalks of the plots.

DOUBLE VERSUS SINGLE PLANTING OP SUGAR CANE. 95

2. At harvest double planting yielded significantly more millable stalks
both in plants and ratoons;

8. In the plant canes, mortality was higher among the double-planted than
among the single-planted population, but insufficiently so to affect the
great initial advantage of the former since it used up just less than
half of it;

4. Two-thirds of the first order (0 — 5 weeks) and a like number of the
second order (6 — 10 weeks) shoots perished before the plant cane
harvest and the two groups together formed only 30 to 36 per cent, of
the whole harvest;

6. Double planting, using less than two tons of extra planting material
per acre, gave a significant increase of 12.98 per cent, in the yield of
plant cane and 12.00 per cent, in the yield of first ratoon cane (a
further advantage is a much better stand at the start and the almost
total elimination of the expense of supplying blanks) ;

6. No significant differences were observed between the weights of cane
per stalk, the sucrose contents of the cane, the juice purities or the
glucose ratios from single as against double planting, but the latter
produced significantly longer late (after 10 weeks) stalks as plants.

Catalogue of the lepidoptera rhopalocera

(BUTTERFLIES) OF BRITISH GUI AN A— ( Contd.)

ARTHUR HALL, F.R.Ent.S.

145. PYRAMEIS CARDUI.

Papilio cardui, Linnaeus, Faun. Snec. p. 276, n. 1054 (1761).'

I took this cosmopolitan and migratory species at Bartica but it is at
present a rarity in South America.

146. PYRAMEIS MYRINNA.

P. viyrinna, Doubleday, Gen. Diurn. Lcp. p. 203, n. 9 ("849).

In the British Museum from Mt. Roraima.

147. Precis lavinia.

Papilio lavinia, Cramer, Pap. I, t. 21, C, D (1775).

Generally distributed and common in open weedy places. It is very
variable and a number of forms of no local constancy have been named. The
form most prevalent in British Guiana, at any rate near Georgetown, is evarete
Cramer which has no blue gloss on the hind wings.

148. ANARTIA JATROrHAE.

Papilio jatrophac, Linnaeus, Mus. Ulr. p. 269 (1764).

One of the commonest butterflies nearly everywhere, preferring dry spots
and open fields. Although so abundant nothing seems to be known of its
early stages.

149. Anartia AMATHEA.

Papilio amathea, Linnaeus, Syst. Nat. I, p. 478, n. 118 (1758).
Generally distributed and common. Unlike A. jatrophac it is partial to
damp places such as the borders of trenches by the roadside.

150. Eunica sophonisba.

Papilio sopkonisba, Cramer, Pap. Ex. IV, t. 295, A, B (1782).
Demerara River ; Tumatumari ; Potaro Road ; Barima River. Always rare
and solitary. I have specimens dated March, July and August.

151. Eunica amelia.

Papilio amelia, Cramer, Pap. Ex. II, t. 136, B, C (1779).

Singly from the Mazaruni and Potaro Rivers but always very scarce.

152. Eunica viola.

E. viola, Bates, Journ. Ent. II, p. 199, n. 34, t. 9, f. 4 (1864).
Carimang River. Also a female in my collection from “ British Guiana ”
collected by R. Haensch.

153. Eunica orphise.

® Papilio orphise, Cramer, Pap. Ex. I, t. 42, E, F (1776).

A female from Omai in the British Museum; Berbice River (Coll. Ent.

Div.)

CATALOGUE OF THE LEP1DOPTERA RHOPALOCERA OF BRITISH GUIANA. 97

154. Eunica ANNA.

Papilio anna, Cramer, Pap. Ex. Ill, t. 281, A, B (1782).

I have a single female of this species from Friendship on the Berbice River
(H. C. Patoir).

155. Eunica moninia.

Papilio moninia, Cramer, Pap. Ex. IV, t. 387, F, G (1782).

In the British Museum from Demerara.

156. Eunica malvina.

E. malvina, Bates, Journ. Ent. II, p. 195, n. 21, t. 9, f. 2, 2a (1864).
Omai; Carimang River.

157. PERIA lamis.

Papilio lamia, Cramer, Pap. Ex. Ill, t. 238, E (1782).

Bartica; Carimang River. Rather rare.

158. Temeris laothoe.

Papilio laothoe, Cramer, Pap. Ex. II, t. 132, A, B (1779).

Demerara River; Friendship on the Berbice; Bartica; Omai; Kaieteur
Falls; Mabaruma. Not very common although widely distributed.

159. Catonephele acontius.

Papilio acontius, Linnaeus, Mant. Plant, p. 537 (1771).

Bartica; Kaieteur Falls; Mabaruma. Not rare in forest districts.

160. Catonephele numilia.

Papilio numilia, Cramer, Pap. Ex. II, t. 81, E, F (1779).

A female from “ British Guiana ” in the British Museum.

161. Ness vea obrinus.

Papilio obrinus, Linnaeus, Syst. Nat. I, p. 470, n. 78 (1758).
Demerara River; Parika; Berbice. Rather common at Parika from
December to February, flying in deep shade but settling on leaves where a spot
of sunshine breaks through.

162. Nessaea batesii.

Epicalia batesii, Felder, Wien. Ent. Mon. IV, p. 237, t. 3, f. 3, (1860).
Demerara; Carimang River, Kuturi Sources. Much rarer than the preced-
ing species.

163. DYNAMINE ATHEMON.

Papilio athemon, Linnaeus, Syst. Nat. I, p. 484, n. 157 (1758).
Demerara River; Omai.

164. Dynamine decima.

Eubagis decima, Hewitson, Ex. Butt. I, Eubagis t. 1, f. 4-6 (1852).

A feihale from the Carimang River has the white markings greatly reduced
as compared with typical specimens from the Lower Amazon and may represent
a new race.

165. Dynamine onias.

Eubagis onias, Hewitson, Ex. Butt. II, Eubagis t. 2, f. 13-15 (1857).

A single female from “ British Guiana ” (Parish) in the British Museum.

f)8 AhRictiLTijRA'L JOURNAL OP BRITISH GUIaNA. fX, &

166. DYNAMINE RACIDULA.

Eubagis racidula, Hewitson, Ex. Butt. I, Eubagis t. 1, f. 2, 3 (1852).
Potaro River; Kaieteur Falls.

167. Dynamine mylitta.

Papilio mylitta, Cramer, Pap. Ex. Ill, t. 253, D, E (1782).

The commonest species of the genus. Parika; Omai; Quonga. Probably
to be found in most forest localities.

168. Callicore clymena.

Papilio clymena, Cramer, Pap. Ex. I, t. 24, E, F (1775).

Quonga; Mabaruma; Mt. Roraima; Kuturi River; Upper Corentyne.
Apparently rare in the Guianas although often abundant in other parts of South
America.

169. Catagramma IDAS.

Papilio idas, Miiller, Natursystem, I, p. 633, t. 19, f. 11 (1774).

One of the rarest butterflies of the Colony. There is a damaged female
in the Georgetown Museum and 1 have seen two or three specimens from British
Guiana but none with any definite localities. Further information about the
species would be welcome. Two females from Demerara (C as tell) in the
British Museum.

170. Catagramma astarte.

Papilio astarte, Cramer, Pap. Ex. Ill, t. 256, C, D (1782).

A male in the British Museum from Friendship, Berbice River, and a
female from “ British Guiana ”.

171. Catagramma cynosura amazona.

C. amazona, Bates, Jour. Enl. II. p. 209 n. 59, t. 10, f. 5, 5a (1864).
A pair from the Kaieteur Falls (A. Hall) is the only record so far.

172. Callithea leprieurii.

C. leprieurn, Feisthamel, Rev. Zool. 1835, t. 122.

Mr. W. J. Kaye saw this species near Bartica but was unable to capture it.

173. Gynaecia dirce.

Papilio dirce, Linnaeus, Syst. Nat. I, p. 477, n. 117 (1758).

Common in many wooded places, settling on tree trunks with the wings
closed. The early stages are wellknown, the larva feeding upon Cassia.

174. Callizona acesta.

Papilio acesta, Linnaeus, Syst. Nat. I, p. 479, n. 127 (1758).

Annai; Berbice; Upper Real; Mabaruma. Similar in habits to Gynaecia
dirce but much rarer.

175. Haematera pyramus thysbe.

H. thysbe, Doubleday & Hewitson, Gen. Diurn. Lep. t. 30, f. 4 (1848).
In the British Museum from Quonga (H. Whitley).

476. Ageronla februa.

A. februa. Htibner, Samml. Ex. Schmett. (1816-24).

Fairly common in wooded places.

CATALOGUE OP THE LEPlDOPTERA RHOPALOCERA OP BRITISH GUIANA. <J9

177. Ageronia IERONIA.

. Papilio feronia, Linnaeus, Syst. Nat. I, p. 473, n. 05 (1758).
Common and generally distributed. Like all species of the genus it settle*
upon tree trunks with expanded wings. It makes a loud clicking sound when
flying.

178. Ageronia amphinome.

Papilio amphinome, Linnaeus, Syst. Nat. I, (2', p. 779, n. 176 (1767).
Not rare at Parika.

179. Ageronia arinome.

Peridromia arinome, Lucas, Rev. Zool. 1853, p. 312.

Kuturi Sources (G. A. Hudson, Jan.-Feb. 1936) ; Demerara River; Groete
Creek, R. Essequibo (G. Brinsley in Coll. Ent. Div. )

180. ECTIMA IONA.

E. iona, Hewitson, Gen. Diurn. Lop., t. 42, f. 4 (1849).

Annai; Potaro Road; Mabaruma. Always a rare species. Like the
Ageroniae it settles on tree trunks with the w’ings expanded.

181. Didonis bibus.

Papilio biblis, Fabricius, Syst. Ent. p. 505, n. 261 (1775).

Omai. Apparently rare in the Guianas.

182. CYSTINEURA CANA.

C. cana, Erichson, Schomb. Reisen III. p. 599 (1818).

Annai; Quonga.

183. Vila emilia.

Papilio emilia, Cramer, Pap. Ex. Ill, t. 223, E, F (1782).

King Frederick William Falls on the Corentyne (G. A. Hudson).

184. Pyrrhogyra neaerea.

Papilio neaetea, Linnaeus, Syst. Nat. I, p. 479, n. 126 (1758).

Demerara River; Parika; Mabaruma (llall) in Coll. Ent. Div. In the form
rcducta Hall from Parika (and French Guiana) the white bands are only half
the normal width and ab. mclunotica Talbot is a unique abberration from British
Guiana having the bands nearly obsolete.

185. Pyrrhogyra crameri.

P. crameri, Aurivillius, Kong. Svensk. Vet. Akad. Handl. IX, p. 98.
Parika; Mabaruma. Not uncommon where found.

186. Pyrrhogyra stratonicus.

P. stratonicus, Fruhstorfer, Stett. Ent. Zcit. 1908, p. 36.

I took a female of this species at Mabaruma in January 1930. As the
only other known specimens have come from the Peru-Bolivian frontier its
existence in British Guiana is a little surprising. .

187. MEGALURA CHIRON.

Papilio chiron, Fabricius, Syst. Ent. p. 452, n. 40 (1775).

Upper Corentyne River (G. A. Hudson) ; “ British Guiana” in the British
Museum. An abundant species in most parts of South America.

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

tx. 2.

100

188. Megalura orsilochus.

Papilio orsilochus, Fabricius, Gen. Ins. p. 252 (1777).

Annai; Carimang River; Kaieteur Falls; Mabaruma. A very graceful
species on the wing and never common.

189. Megalura peleus.

Papilio peleus, Sulzer, Gesch. Ins., t. 13, f. 4 (1776).

Berbice.

190. Hypolimnas misippus.

Papilio misippus, Linnaeus, Mus. Ulr. p. 264 (1764).

This East Indian species is a recent introduction into South America. It
is to be found at Parika, Mabaruma and other places in the Colony.

191. Victorina steneles.

Papilio steneles, Linnaeus, Syst. Nat. I, p. 465, n. 124 (1758).
Generally common and often abundant.

192. Adelpha mesentina.

Papilio mesentina, Cramer, Pap. Ex. II, t. 162, B, C (1779).

Annai.

193. Adelpha tizona kayei.

A, tizona kayei subsp. nov.

Description. — Differs from all the described forms of A. tizona Feld. In
the fore wings having three large subapical spots completely united with one
another and with the oblique discal band, giving the latter the appearance of
being forked. It has a superficial resemblance to A. ximena Feld. Potaro
River. Type, a female in the collection of W. J. Kaye.

194. Adelpha cocala.

Papilio cocala, Cramer, Pap. Ex. Ill, t. 242, F, G. (1782).

Demerara River; Annai; Omai; Carimang River; Mabaruma.

195. Adelpha pseudococala.

A. pseudococala, Hall, Nov. Zool. XXXIX, p. 10 (1933).

Mabaruma; Kaieteur Falls. This species is difficult to distinguish from
A. cocala but the Rev. Miles Moss has bred it at Para from totally different
larvae and pupae.

196. Adelpha erotia.

Heterochroa erotia, Hewitson, Ann. Mag. Nat. Hist. XX, p. 269, t. 20,
f. 3 (1847).

I took a single very typical specimen at Mabaruma.

197. Adelpha thesprotia.

Heterochroa thesprotia, Felder, Reise Nov. Lep. Ill, p. 419, n. 653
(1867).

Berbice; Takutu; Oronoque-New River confluence (G. A. Hudson).

198. Adelpha delphicola.

A. delphicola, Fruhstorfer, Koch-Grunberg’s Reise II, p. 348.

A specimen in my collection from Friendship on the Berbice River (H. C.
Patoir).

CATALOGUE OF THE LEPJDOPTERA RHOPALOCERA OF BRITISH GUIANA. 101

199. Adelpha PHLIASSA.

Nympkalis phlia&sa, Godart, Enc. Meth. IX, p. 373, n. 78 (1823).
Annai; Berbice; Ida Sabina.

200. Adelpha cytherea.

Papilio cytherea, Linnaeus, Syst. Nat. I, p. 481, n. 139 (1758).

The commonest species of the genus, usually in damp spots near second
growth forest.

201. Adelpha iphiclus.

Papilio iphiclus, Linnaeus, Syst. Nat. I, p. 486, n. 172 (1758).

Demerara River, Mabaruma.

202. Adelpha melona.

Heterochroa melona, Hewitson, Ann. Mag. Nat. Hist. XX, p. 258, t. 20,
f. 2 (1847).

Bartica; Mabaruma; Carimang River. A fairly common species in forests.

203. Adelpha serpa.

Heterochroa set pa, Boisduval, Spec. Gen. I, t. 8, f. 4 (1836).

In the British Museum from the Carimang River.

204. Adelpha paraena.

Heterochroa paraena, Bates, Journ. Ent. II, p. 331, n. 167 (1865).

A female in my collection from "British Guiana” (Parish).

205. Chlorippe agathina.

Papilio agathina, Cramer, Pap. Ex. II, t. 167, E, F (1782).

Qnonga; Omai; King Frederick William Falls; Upper Corentyne.

206. Historis OD1US.

Papilio odius, Fabricius, Syst. Ent. p. 457, n. 60 (1775).

Parika; Omai. Not uncommon.

207. COEA ACHERONTA.

Papilio acheronta, Fabricius, Syst. Ent. p. 501, n. 249 (1775''.

Taken by J. G. Myers on the Rupununi Savannahs (Nov. 1933).

208. Prepona demophon.

Papilio demophon, Linnaeus, ‘Syst. Nat. I, p. 464, n. 36 (175P).

Omai; Parika; Bartica, Mabaruma; Berbice (Coll. Ent. Div.) Fairly
common and easily attracted to sugar on tree trunks.

209. Prepona meander.

Papilio meander, Cramer, Pap. Ex. I, t. 12, A, B (1775).

Carimang River.

210. Prepona pheridamas. .

Papilio pkeridamas, Cramer, Pap. Ex. II, t. 158, A, B (1779).

In the British Museum from Omai.

211. Prepona antimache.

Morpho antimache, Hiibner, Verz. Bek. Schmett. p. 49 n. 458 (1816).
There are Specimens in the Georgetown Museum without definite locality.

102 AGRICULTURAL JOURNAL OP BRITISH GUIANA. [X, 2.

212. PREPONA DEXAMENES.

P, dexamenes, Hoppfer, Stett. Ent. Zeit. 1874, p. 852, n. 64.

A male from Demerara in the British Museum.

213. Prepona omphale.

Morpho omphale, Hiibner, Verz. bek. Schmett. p. 49, n. 454 1816) .
Represented in the Georgetown Museum but with no indication as to
whence the specimens came. There is no reason, however, to doubt its
existence in the Colony.

214. AGRIAS CLAUDIA.

Papilio claudia, Schulz, Naturf. IX, p. 100, t. 2 (1776).

This fine species is extremely rare and its headquarters in British Guiana
are not definitely known. There are two or three specimens in the Georgetown
Museum believed to have come from the Demerara River or Berbice and a dark
aberration called info mils Fruhstorfer is said to have come from
New Amsterdam but I have not seen an authentic British Guiana specimen
in any English collection.

215. Megistanis baeotus. '

M. baeotus, Doubleday & Hewitson, Gen. Diurn. Lop. t. 48, f. 2 (1850).
Upper Kuturi River (G. A. Hudson).

216. Megistants japetus.

M. japetus, Standinger, Ex. Tagl. I, p. 174, t. 60 (1888).

Oronoque River, near the Brazilian frontier. The hitherto undescribed
female of this species has the bands of the upperside yellow instead of blue.

217. Anaea heue.

Papilio helie, Linnaeus, Syst. Nat. I, p. 475, n. 103 (1758).

Marudi Mountain, Rupununi District (L. H. J. Ashburner). Th' 0
species is probably better known under the name of A. ryphea, Cramer.

218. Anaea eribotes.

Papilio eribotes, Fabricius, Syst. Fnt, p. 484, n. 183 (1775).

Demerara River; Kaieteur Falls.

219. Anaea leonida.

Papilio leonida, Cramer, Pap. Ex. IV, t. 388, C, D (1782).

An old specimen in my collection is labelled “ Georgetown ”. If this is
correct it was probably collected before the bush had been cleared from the
vicinity. It is a fairly well known species in Dutch and French Guiana.

220. Anaea pithyusa morena.

A. pithyusa morena Hall, “Entomologist” LXVIII, p. 224 (1935).
Mabaruma; Kuturi River; Upper Corentyne. It is a little strange that
nearly all the specimens of this race which come to hand are females whereas
in the typical race from Central America the males are far more abundant. *

221. Anaea glauce.

Nymphalis glauce, Felder, Wien. Ent. Mon. VI, p. 119, n. 132 (1862).
Kaieteur Falls. (March 1936, A. Hall).

CATALOGUE OP THE LEPIDOPTERA RHOPALOCERA OF BRITISH GUIANA. 103

222. Anaea MORVUS.

Papilio morvus, Fabricius, Syst. Ent. p. 484, n. 184 (1775).
Carimang River; Bartica; Mabaruma; Mt. Roraima. Usually the
commonest species of the genus.

223. Anaea rasilea.

Papilio hasilca, Cramer, Pap. Ex. IV, t. 329, E, F. (1782).

Kuturi Sources (G. A. Hudson, Jan.-Feb. 1936).

224. Anaea odilia.

Papilio odilia, Cramer, Pap. Ex. IV, t. 329, C, D (1782).

In my collection from Friendship on the Berbice.

225. Hypna clytemnestra.

Papilio clytemnestra, Cramer, Pap. Ex. II, t. 137, A, B (1779).

Annai; Takutu; Kaieteur Falls; Kuturi River. Most British Guiana
specimens belong to the rare typical form in which the fore-wings have no
subapical spots.

226. Zaretes isidora.

Papilio isidora, Cramer, Pap. Ex. Ill, t. 235, A, B, E, F (1782).
Parika. As this is a common species in neighbouring countries it is
probably to be found elsewhere if looked for.

227. SfDERONE MARTHESIA.

Papilio marthcsia, Cramer, Pap. Ex. II, t. 191, A, B (1779).

Potaro River (coll. W. J. Kaye). The older name of this fine species is
probably S. yalanthis Cramer but the figure of the latter is sufficiently poor
to be a little doubtful.

228. Protogonius iiippona.

Papilio hippova, Fabricius, Gen. Ins. p. 265 (1775).'

Omai, Berbice; Parika; Mabaruma.

229. LlBYTHEA CAR1NENTA.

Papilio carinenta, Cramer, Pap. Ex. IT, t. 108, E, F (1779).

Potaro River <W. J. Kaye). This particular genus probably belongs to the
Nymphalidae and not to the Erycinidae.

l'a mil y ER Y C I N I DA E.

One of the peculiarities of this family is that many species only occur
singly. A specimen of a certain species may be taken at a particular spot
and no others may be found there again for a long period. For this reason
many of our records are taken from single specimens. A. few species
are common and are notable for their habit of settling on the under surface
of leaves with the wings expanded flat, so that they seem to suddenly
disappear from the sight of the observer.

AGRICULTURAL JOURNAL Of BRITISH GUIANA. IX, 2.

Sub-family EUSELASIINAE.

2S0. Euselasia uzita.

Eurygona uzita, Hewitson, Ex. Butt. II, Eurygona t 2, f. 12, IS
(1852').

Annai. Apparently locally common.

231. Euselasia mys.

Eurygona mys, Herrich-Schaeffer, Ex. Schmett. f. 37, 38 (1835).
Quonga; Mt. Roraima.

232. Euselasia eucritus.

Eurygona eucritus, Hewitson, Ex. Butt. II, Eurygona t. 2, f. 14-16
(1852).

Carimang River.

233. Euselasia zena.

Eurygona zena, Hewitson, Ex. Butt. II, Eurygona t. 8, f. 74, 76 (1860).
Upper Cuyuni River (J. G. Myers). The single specimen, a female, has
the red spot on the hind wings much smaller than in the typical form and may
represent a new race.

234. Euselasia eubotes.

Eurygona eubotes, Hewitson, Ex. Butt. I, Eurygona, t. 7, f. 64 (1856).
Annai.

235. Euselasia eutychus.

Eurygona eutychus, Hewitson, Ex. Butt. I, Eurygona t. 5. f. 44-46.
(1856).

Kuturi River.

236. Euselasia melapiiaea.

Erythia melaphaea, Hiibner, Zutr. Ex. Schmett. f. 209, 210 (1823).
Kaieteur Falls; Carimang River.

237. Euselasia orfita.

Papilio orfita, Cramer, Pap. Ex. II, t. 112, F (1779).

Annai; Carimang River; Mabaruma.

238. Euselasia eulione.

Eurygona eulione, Hewitson, Ex. Butt. I, Eurygona t. 6, f. 52 (1856).
Potaro River.

239. Euselasia cafusa

Eurygona cafusa, Bates, Journ. Linn. Soc. IX, p. 422, n. 23 (1868).
Annai.

240. Euselasia eustachius licinia.

Eurygona licinia, Qodman, Trans. Ent. Soc. 1903, p. 531, t. 20, f. 6.
Type in the British Museum from Mt. Roraima.

241. Euselasia utica.

Eurygona utica, Hewitson, Ex. Butt. I, Eurygona, t. 3, f. 29-31 (1854),
Annai.

[To be Continued]

NOTES.

The Foreshore Vegetation east of Georgetown . Since the last notes
on the subject appeared in this Journal (VII, p. 191, 1936) further interesting
changes have taken place in the configuration of the shore line, which have been
reflected in the vegetation behind it,

A. high caddy beach has been formed by wind and wave action at the sea-
ward edge of the courida belt from Bel Air to La Bonne Intention, and extends
westwards as far as Kitty groyne. The back of this beach (i e. y the landward side)
is forming a new shore line, and is only covered by spring tides. This means that
the original muddy foreshore between the new beach and the Sea Wall, the area
which has been carrying Courida (Atuminia tiitida) and Rice Grass (Spartina
hraxilienm) in recent years, is now left dry between spring tides, except for a
few small areas covered by water coming in through natural drainage channels
that pass out through the beach at intervals. In this area considerable changes
in the vegetation are taking pbce and both the Courida and the Spartina are
dying out.

We may refer to the Courida firat, as the loss of this has been more
noticeable. In former published notes on the foreshore vegetation, reference has
been made to the “Mangrove Belt” to denote the belt of trees growing on the
muddy foreshore. This belt includes, besides Avicmnia, a certain amount of
fjityuncularia ramnow and occasional trees of Jihizophora spp., but as in the
locality under discussion the A vicenn ia is entirely dominant, the tree belt will
be referred to here as * Courida

In 1934 a thick belt of Courida* which had grown up within the previous
few years, extended from Ogle Koker trench to Lifiendaal, and appeared to be
stretching on towards Kitty. As was pQinted out in the last Notes, a portion of
this belt of trees was almost entirely cut down in 1934, the part cleared extending
from a line opposito the east end of the promenade backing the sea wall at
Turkeyen to the western fringe of the Courida opposite Bel Air Hotel. From
Turkey en east- ward to Ogle Koker however the trees remained. It i3 first of all
interesting to note that the expanse of bare mud left by this clearance, and described
in the previous Notes, is today still bare with the exception of a few widely
scattered and very small clumps of Spirtina and some struggling Courida seedlings,
both of which occur in depressions or on the edge of drainage channels.

In 1936, however, it became noticeable that the trees near the wall in the
remaining portion of the Courida belt, in front and to the east of Turkeyen, were
beginning to die, starting from the west end of the belt. During 1937, this
became more marked, and in 1938 the whole belt nearly as far as Ogle Koker died

106

AQBICtJLTOEAL JOURNAL 0? BRITISH GUIANA*

tX,2.

out, with the exception of a narrow margin of healthy trees on the seaward
side, immediately behind the recently formed beach. (Plate II, Fig. 1)
which should be compared with Plate II, Fig. 2, he. cit.).

On walking out over the mud flat beside the bolt of dead trees, the mud
being fairly firm on dry days except where intersected by drainage rivulets, it
could be seen that the Courida trees, with the exception of a few on which one
or two green branches remained, were all diied up and dead, and that the
usual pneumatophores which cover thickly the mud below healthy living trees
were absent. But on nearing the back ot the beach, the bare mud, which
was there soft, was occupied by large patches ol Spartina, and a strip of Courida
trees about f>0 yards wide, immediately behind the beach, remained quite green
and healthy, with abundant pneumatophores. The seaward edge of the
Courida ended abruptly on firm sand, which was hare except for isolated plants
of Spartina and a lew creeping plants ol Oiab (liass (Spo robot tt.s nrgim'eus.)

This death of all the Courida trees, which wm e twenty feet high and more
and some 9 or 10 years old, taking place as it did within a \ ear or two, over
a large area, is rather difficult ol explanation. *The lollowing suggestion is
however put forward for what it may be worth.

Courida trees can be found in habitats varying from the muddy foreshore
immediately behind the neap tide mark to those cases where old trees are fonnd in
lowlying land behind the Sea Wall, where the sea never penetrates, but where
the water is sometimes brackish (e.g.\ on Thomas Lands, near the Sea Wall). In
such latter situations however, only mature plants can exist, and seedlings cannot
become established. But in places where Courida grows well, there is
movement of the water about the roots, more especially on the tidal foieshore,
where the soil water moves up and down with ever> lido. Since the formation
of the new beach, however, this subsoil movement of the water in the
area behind it, which is only covered by spring tides, is very greatly reduced,
leaving the Courida for long periods in wet mud in which the water has become
practically stagnant. This it is suggested causes asphyxiation and death
of the plants. A contributory factor may possibly be found in the raising of
the mud level by the inwash of ‘sling' mud brought by the spring tides, but
this has not raised the general level of the mud \er$ rapidly, and in healthy
trees the pneumatophores would doubtless develop to keep pace with it.

But not only has the Courida been killed on this foreshore mud flat ; the
Spartina too, is dying. Whereas two years ago it extended from opposite Bel
Air Hotel westward to Kitty groyne, it is now dying back from the east as far as
the Police riding ground, leaving nothing but bare mud. The dry periods
between spring tides probably account tor this, the caked surface that forms
faring these periods being quite inimical to the Spartina.

On these bare areas of mud, covered only by spring tides, where the
Spartina and Courida have died, and also on the area originally cleared of

Plate II

Fig. 2.— Rice Grass West of Kitty Jetty, May 1939. cf Plate II, Fig 1, loc at

N0TB8.

107

Courida by felling, little or nothing seems able to become established. It 'was
thought that possibly the Black Mangrove ( Rhizophora spp.) might be grown,
and with this end in view some small plots were fenced with barbed wire, sites
being selected both close to the sea wall and further out, and Rhizophora seed-
lings brought from the Demerara River were pi mted therein. They did not
however prove satisfactory and after a month or so all had died out, though
possibly if greater care and attention could have been given them some of the
plants might have become established.

It would seem that no vegetation will be able to establish itself naturally
on this area until it is no longer covered even by spring tides, and the salt can
leach out of it. At present the dry periods between spring tides prevent the
establishment of halophytes, and the salt content of the mud, consequent upon its
periodic covering by sea water, is too great for other forms of plant life. — E B.M.

Plant Inspection Service. During the period March 1 to May 111, 1939,
73 import certificates were issued for plant material entering the Colony and
34 export certificates for plant material leaving the Colony.

PLANT AND SEED EXCHANGE.

For the period ending May 1939.
INTRODUCTIONS.

Name

Quantity.

Whence Supplied

Economic.

Sugar Cane — 7 varieties

Cuttings of each

Plant Quarantine Station,

Dept, of Agriculture,
Trinidad.

Rice— 6 varieties

6 lb.

Rice Research Officer, Burma.

„ 8 varieties

1 oz. eich

Botanical Assistant,

Assam, India.

1G samples

2 oz. each

Botanical Assistant,

Kariraganj Farm, Assam,
India.

Musa textilis

suckers

Agricultural Superintendent,
St. Vincent.

Tobacco Seed— Hickory Pryor

2 oz.

T. W. Wood & Sons,

Virginia,

Vegetable Seeds

2 lb.

Messrs. Sutton & Sons,
Reading, England.

Sunn Hemp ( Crotalaria juncea)

4 lb.

Imperial College of

Tropical Agriculture,
Trinidad.

Soya Bean— 5 varieties

•Jogun, Hokkaido, Willomi,
Imperial and Emperor

2 oz. each

[Jniv. of Illinois, U.S.A.

Ornamental.

Culophyllum Inophylhm

2 oz. |

F. G. Walsingham, Harvard
Univ., Atkins Institution
of the Arnold Arboretum,
Cuba.

Gmelina arbor ea

3 oz.

Director of Agriculture,
Reduit, Mauritius.

Coi indeia madagascanetms

do.

Araucaria Cunninghamii

do.

Pseudo phoenix sargent ii

4 oz.

Arthur Langlois, The

Retreat, Nassau, Bahamas.

Flower Seeds

2 lb.

Messrs. Sutton & Sons,

Reading, England.

VaHous Ornamental Seeds

7 packets

The Curator, Univ. of

Stellenbosch. South Africa

PLANT AND SEED EXCHANGE— (Conti.)

DESPATCHES.

Name

Quantity

Economic.

Dwarf Bonavist

14 oz.

Padi— 3 varieties

1C oz

» 5 n

1 packet each

ii 4 ,,

do.

ii 4 ,,

do.

„ 10

1 2 oz, each

Beans —3 varieties

Padi No, 711

3 packets

6 oz

Peas <& Beans— 9 varieties

Pineapple— 2 varieties

8 packets

If) suckers

Panama Papaw

1 packet seeds

Ginger — 3 varieties

Pan*' flora hinptda

Roots of each

1 packet

Solatium nessiltflorurn ( Cubiett)

i» M ii

1 packet

Ornamental

Assorted Ornamental Seeds

6 packets

Victoria reijia

1 packet seeds

Assorted Ornamental Seeds

7 packets

Orchids— 2 varieties

Assorted Ornamental Seeds

Orchids —8 varieties

‘cuttings* of each

1 9 packets
‘cuttings* of each

Destination

Dr. D. S. Fernandes, Dept of
Agrl. Economics, Surinam.

The Rice Specialist in charge,
Rice Research Station,
Bihar, India.

Rice Research Officer,
Rangoon. Burma, India.

Botanical Assistant, Govt.
Rice Exptl. Farm, Assam,
India.

Botanical Assistant, Karimgan j,
Assam, India.

Director of Plant Breeding,
Dept, of Agriculture,
Sydney, New South Wales
Australia.

do.

Director, Dept, of Science
& Agriculture, Jamaica.

do.

Director of Agriculture,
Trinidad.

Diroctoi of Agriculture,
Freetown, Sierra Leone,
do.

Director, Royal Botanic
Gardens, Kew, Surrey,
England.

Imperial College of Tropical
Agriculture, Trinidad.

The Superintendent, Govt.

Gardens in Mysore, India.
U,S. Dept, of Agriculture,

Ma> agues, Puerto Rico.
New York Botanic Gardens
U.S.A. (through Mr. Stan*
ley G, Ranger),
do.

Private Collectors,
do.

METEOROLOGICAL DATA — JANUARY TO MARCH, 1939.

Recording Stations &
Months.

Rain-

fall.

NUMllER OF DAYS OF RAIN

Evapo-

ration

Air Temperature
a ad Humidity.

Botanic Gardens.

Total

Inches.

Under .10
Iuch

10 to ,
1 .50 Inch

1 00 Inch 1
to

2 00 Inches i

•<8

Total days

XuOhes

[

1 Minimum. 1

January

12.G1

3.57

83.4

74.9

79.1

] 82.4

February

3.93

o ;

...

4.58

83.3

74.5

78.9

78.7

March

4J>6

•••

5.32

83.5

75.2

79.3

77 4

Totals

21.20

1 13.47 1 ...

...

1 1

' -

Means

...

... !

! i

...

183.4

74 9 79.1 J 79.5

Berbice Gardens,

]

January

5.37

1 7

18. I

...

85.1,

, 74.3

79.7

78.9

February

6.26

1 6

... j

84 1

74.1

79.1

84.3

March

, 12.98

l 10

1 ~

81.3

73.8

79.0|

82.7

Totals

24.61 |

23 |

1 0

...

i •••

...

i...'

1 _

Means

... i

...

8 4.5| 74.1

79 3

81.9

i ___

Onderneeming.

[ 1

January

10 53

1 i

1 ®

! 17

...

| w>.i;

73.9

80 0

1 92 7

February

7.18

i «

» ,

...

' 12 I

...

| 85.4

73.1

79.2

| 93.1

March

8.43

...

1 __

... i

f) |

...

( 85.2

73.3

79.2

[ 93.3

Totals

26.14 1

_21j

6 1

7 j

1 j

1 _

Means

...

... ,

... |

...

85. fij

73.4,

79.5

93.0

Hoiororo,

North West District

1 i

i 1

January

13.29

...

83.2

68.4

75.8

86.1

February

3.53

...

84*2

67.2

75.7

81.6

Ma&h

1.78

...

85.4

68.7

77.0

79,3

Totals

18.60

...

** €

...

•

...

Means

...

"...

84.3

68.1

76.2

82.3

VoL X, No. 3.

September, 1939.

The

Agricultural Journal

British Guiana

PUBLISHED BY

THE DEPARTMENT OF AGRICULTURE

GEORGETOWN, BRITISH GUIANA

Price

••

6d.

DEPARTMENT OF AGRICULTURE.

ADMINISTRATION

Director of Agriculture
Deputy Director

Chief Clerk
Registrar of Banks
Accountant
Record Clerk

Typist Clerks

Probationers

Librarian

Prof. The Hon. J. Sydney Dash.
B.Sc. (Auric.)

(vacant)

L. D. Cleare, F.K. Ent. B. (acting)

Clerical Staff

J, F. Irving, m.o.

W. G. Deiph
A. A. Thorne
Miss D. M. Terrill
( Miss M. Cbeong
Miss S. Lord
( Miss R. Deiph
j P. O. Jackson
S. A. Adams
( M. R. Chase
Miss V. Chan-Choong

RESEARCH BRANCH.

Botany and Plant Pathology

Iiot a Hint— Plant Pathologist and Supei mttnd-
ent< Hot and Harden*'

E. B. Martyn. ha. AM .T \

Technical Actant: X. Persaud

Chemistry

Che mint

D. W. Duthie. M.A., B. 8c . Pta.D., F.l <

A mutant Chemist :

C. L. C. Bourne (on le.ue)

Economica

Agricultural Economist :

H. D. Huggins, M.hv..l>ip. Agr.

Entomology

FnUimologtst :

L. D. (Ueare, F.R. Ent. s.

Technical Assistant : C. Williams

Rice

Assistant Plant llreedn *

P. A. Chan-Choong, B.So.. A.i ( .T A.

Sugar

(In co-operation with the Sugar Producers)
Sugar Agronomist and Plant Breeder :

C. H. B. Williams, M.A., A.uvrju Dm. Apr.

Laburatqry Assistants : H. B. Singh

A. Y. Wan-Ping, Dm. Agr.

Statistical Assistant: J. B. Bourne. F.ss.

FIELD BRANCH

I gricultvra l Superintendents :

Berbice— A. A. Abraham
Demerara, East — E. M. Peterkin (on leave)
Demerara, East Bank — H. D. Huggins,
M.Sc., Du>. Art.

Demerara, West— E. G. Benson, n.sc.,
a.u.t.a., Dip. Agr. (on leave)
Essequibo— T. Bell, b.s.a., a.i.C.t.a.

Assistant Agricultural Superintendent :

West Demerara— E. M. Morgan

Agricultural Instructors :

Bcrbice -(). F. J. Churaman,D>D Agr.
Botanic Gardens— H. A. Cole (on leave)
Demerara, East— C. C. Dowdtng, f.l s.,
f.k.h.s

Agricultural Assistants :

Demerara, East — J. Indrobeharry
Essequibo— H. B. France

Technical Assistants .

Demerara, East — W. A. Bovell
Essequibo— A. W. Sear*

North West District— L. E. McKinnon

Sugar

Field Manager (Central Slot ion J
C. Cameron (on leave)

Field Assistants :

L. A. Forte
B. A. McArthur

LIVESTOCK BRANCH

IV/ermarjy Surgeon :

H A Fraser, B.V. Sc.

METEOROLOGICAL BRANCH

Technical Assistant :

D. D. Blackman

Meteorological Assistant :

J. E. Isaacs

RICE GRADING BRANCH

Grading Inspector;

H. E. H. Gadd

Technical Assistants :

R. R. Robb
G. L. Leitch

ADVISORY BOARD OF AGRICULTURE

Director of Agriculture, Chairman, ex officio .

Deputy Director of Agriculture, Vice-Chairman, ex officio .
Hon. Peer Bacchus
Hon. R. E. Brassington
Hon. J W. Jackson

Hod E. M. Walcott (acting for Hon. F. J. Seaford, o.b.e )
Mr. S. Andries
„ R. B. Hunter
.. W. H. Richards

Members

SUGAR EXPERIMENT STATIONS’ COMMITTEE.

Director of Agriculture, Chairman, ex-officio.
Hon. M. B. G. Austin, o.b.e.

Mr. J. Bee
„ G.M. Eccles
„ J. C. Gibson

„ G. H. Holden
„ A. Murison

Georgetown
Pin. Albion
Pin. Blairmont
Messrs. Booket Bros.
McConnell & Co. Ltd.
Pin. Diamond
Pin. Uitvlugt

Representing
the Sugar
Industry
which main-
tains the
Stations

CO-OPERATIVE CREDIT BANKS’ BOARD.

Director of Agriculture, Chairman, ex-officio .

Dr. the Hon. J. B. Singh
Rev. A. E. Dyett ...

Mr. C. Farnum ...

„ J.L. Wills ...

Members

CONTENTS

(Vol. X, NO. 3.)

Page

EDITORIAL — 111

ORIGINAL ARTICLES.

Acidity and “Active” Alu-
mina in British Guiana

Sugar-Cane Soils ... D. W. Duthic , Ph.D F.I.C. and

C . L. C. Bourtw ... ... 113

Experimental Cultivations in

the North West District ... E . B . Marty n , jB.^4., A.I.C.l'.A. ... 124

The Variety and Fertiliser
Position of the Sugar In-
dustry, V. ... C . 22. 2?. Jtf.A., A.LO.T.A

Dtp. Atfr. ... ... 139

Catalogue of the Lepidoptera
rhopalocera (Butterflies)

of British Guiana. (Could.) ... Arthur Hall , F»R t Ent»S\ ... 146

METEOROLOGICAL DATA ... ... ... ... 170

ILLUSTRATIONS

. Facing Page

Plate I. —Cane Seedlings Growing in Acid Medium ... 114

II.— Fig. 1— Relative Varietal Composition of the Cane
Areas to be harvested in British Guiana
< in 1939 ... ... ••• 1*0

XU. Fig. 2 — Relative Values and Quantities of Fer-

tilisers used on British Guiana Sugar
Estates in 1938 ... ••• 141

The

Agricultural Journal of British Guiana

September, 1939,

EDITORIAL.

FOOD SUPPLIES.

There are many indications that the local agriculturist will advisedly pay
more attention to the production of food crops The Earl de la Warr Nutrition
Committee draws attention to the prevalence in the Colonial Empire of deficiency
diseases, lowered resistance to other diseases and general impoverishment of
well-being and efficiency. One of the ways of combating this condition is to
increase the supplies of fruit and vegetables in the home plot. In the Editorial
of the Farm Journal of January 1938 it was stated : “ The family cow for the

farm, for instance, should be more in evidence so that even those who cannot
afford to purchase milk in sufficient quantities may not be deprived of its
benefits. Fruit trees ( oranges, papaws, etc.) may be put in, in vacant spots,
even if the conditions are not considered ideal and even if the types or varieties
which succeed are not the most suitable from the cash sale point of view. The
kitchen garden with its supply of vegetables — even if the grower is not near
enough to a populous centre for truck gardening to be profitable — should be
established to supply the home's needs. Thus can oui farmers take an
important step in safeguarding and increasing their supplies’ of protective
foods. To induce thinking along these lines the British Guiana Department of
Agriculture is encouraging its district officers to mention this feature
prominently when opportunities for group talks occur.”

*An even more insistent demand on farmers to think along these lines is
now made by the declaration of war. The recent wars that have been fought
have not been short; interference with shipping and so with supplies has been
a chief weapon ; it is probable, therefore, that imports, even if obtainable, will
be costly. Clearly, an increase in the production of articles planned to render
the Colony self-sufficient is likely to prove not only desirable and helpful but
necessary.

112

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X. 8.

During the first half of this year reports indicated that an increase of
existing sugar export quotas was likely to take place because of short crops in
India and Europe and the accumulation of war supplies by different Govern-
ments. With the outbreak of war further revision is not improbable; it is
possible that with beet sugar production disorganized in Europe, colonial out-
put, instead of being restricted, may be encouraged. The sugar estates in
cane farming areas have already notified fanners that increased plantings
should be proceeded with. The Department has endeavoured consistently to
foster cane farming which appears in many ways to be an industry likely to
afford a type of enterprise well suited to our agricultural population. In
conjunction with other of the Department’s efforts an economic survey was
carried out among the cane farmers at East Demerara. As a result attention
was drawn to certain cane-farming practices which can advantageously be
modified. For example, although it is known that since the survey was taken
many farmers are trying the higher yielding varieties, up to 3 years ago
practically all (91%) of the farmers stated that D 626 was the only variety
they had in cultivation. It was found that although extremely few farmers did
not use fertiliser, the applications in a large percentage of cases were only half
of what they should be. It was interesting to note a tendency for the younger
farmers to use more fertiliser than the older farmers and for East Indians to
use more than West Indians. These and other findings make it possible for
the Department’s extension officers to supply cane farmers with definite and
specific advice.

Rice production should also be expanded, for this crop provides the supply
of a staple article of diet which is certain to find an increasing demand both
locally and in the neighbouring West Indian Colonies. In this connection the
growth of a spring crop where conditions permit suggests itself as a practice
which is to be encouraged for more general adoption. It has for a long
time been claimed by growers that low prices have been the chief factor
discouraging increased plantings; the likelihood of sharp price advances
is in itself likely to give production an initial and probably important
fillip.

These are a few indications of the changing situation which farmers are
being called on to meet. Peas and beans can and should be considerably
extended. Food committees have been appointed — one to control prices and one
to encourage food crop production. Agriculturists and farmers generally will
be advised to prepare for the end of the year rains so that no delay in getting
cultivations established will be experienced. The question of seed supplies and
planting material generally is receiving the attention of the Department.

ORIGINAL ARTICLES.

ACIDITY AND “ACTIVE” ALUMINA IN
BRITISH GUIANA SUGAR-CANE SOILS.

D. W. DUTHIE, ph.d., F.I.C.,

Chemist,

AND

C. L. C. BOURNE,

Assistant Chemist,

Department of Aoriculturc, British Guiana.

I. Introduction.

In 1932 Follett Smith (8) pointed out that, during the past thirty years,
a marked change has taken place in the reaction of the topsoils of the sugar
cane lands of this Colony. In 1908 the water extracts of 87 samples examined
by Sir John Harrison were all alkaline to litmus, while in 1931-32 only 12
topsoils out of 2,893 (0.4 per cent.) had a reaction value above the neutral
point (pH 7). Quoting Follett Smith “It is likely that this marked increase
in soil acidity, which has taken place in a comparatively short space of time,
is progressive, and that, if the present system of agriculture is continued, the
cane soils of the Colony will in the future reach a degree of acidity incompat-
ible with the growth of heavy crops of cane ”.

Later, Follett Smith (9) showed that applications of sulphate of ammonia
totalling 12-18 cw r t. per acre over a three-crop cycle caused a statistically signifi-
cant depression of the topsoil pH. Manurial trials with ground limestone and
slaked lime have shown that, generally speaking, flood-fallowed clay soils do
not respond to liming materials, whereas unflooded clay soils do. On pegasse
soils there has been some response to small dressings (1 ton per acre) but no
economic return from dressings which approached the lime requirement of the
soils.

It has been recommended by this Department that, as a preventive measure",
one ton of limestone per acre should be applied at planting, this being more
than sufficient to counteract the acidity developed during the previous crop
cycle. This liming programme was designed as an insurance against the
possible effects of extreme acidity, but it is necessary to find the factors
involved in this change from alkaline to acid in order to judge whether or not
the growth of cane will ultimately be affected.

II. Soil Acidity.

For the present purpose it is preferable to consider particularly the acidity
of the sugar cane soils of this Colony, rather than to generalise on a chemical
subject whiclfc is too complex for simple explanation. Harrison - (12) found

Ill

AGRICULTURAL JOURNAL 07 BRITISH GUIANA.

[X» 8.

that the alkalinity of the clay soils was due to the presence of sodium carbon-
ate and the double carbonate of sodium and magnesium. During the dry
season, evaporation of the soil waters resulted in an increased concentration
of these salts, sometimes to an extent which injured the cane. Thus, soil
alkalinity may be undesirable, and Harrison ascribes the improvement of these
soils on cultivation to be due largely to the washing out of sodium salts, and to
the correction of the alkalinity of the subsoil waters when sulphate of ammonia
is applied as a fertiliser. This shows that the acidifying effect of sulphate
of ammonia was not harmful to these saline soils, as it favoured the washing
out of the undesirable sodium salts by converting them from carbonate to the
more soluble sulphate.

Evidence of the effect of flood-fallowing and irrigation in washing out
salts from the soil was given by Follett Smith. He analysed the water on five
flood-fallowed fields (7), and from his figures it appears that flood-fallowing
removes from one acre 2 to 4 tons sodium chloride, 3 to 4 tons magnesium
sulphate, and $ to 1J tons carbonate of lime. In another investigation (S') he
estimated the total salt content of the top and subsoils of three fields which
were suspected of being affected bv excessive saljrtity. Two sets of samples
were taken, with an interval of five months, during which time the area was
flushed on five occasions, and in addition both banks were forked after plant-
ing, a bed-drill two feet wide by one foot deep was made in the original first
bank, and the small drains of the fields were dug an extra shovel deep. Table
I gives the salt content of the three sets of soil samples before and after the
treatment.

Table I.

Per Cevt. Soluble Salts.

Date sampled :

1.4.32.

27.8.32

Tons removed
per acre-foot.

Field 1.

Topsoil

0.159

i 0.088

1 3

Subsoil

0 165

0 121

0.8

Field 3.

Topsoil

0.250

0 090 1

3.0

Subsoil

0.307

0 289

1.4

Field 6

Topsoil

0.314

0.099

3.8

Subsoil

0.407

0.259

2.6

Thus the original change from alkaline to slightly acid, which took place
in the coastland clay soils, was probably due to the washing out of alkaline
salts and not to the liberation of acid from sulphate of ammonia. Padi soils
should give some idea of the acidifying effect of removing salts, as they have
bdkn cultivated for many years without manuring, and under conditions which
favour the washing out of soluble salts. It is reasonable to assume that the
padi soils of this Colony were originally alkaline, like the sugar cane soils,

PLATE I.

t-i OI

*-4 ^
r-i CM

O ^
t-i CM

w e

•5

00 cc g

-r

CO -3

CM p-

ACIDITY AMD " ACTIVE ” ALUMINA IN BRITISH GUIANA 0UGARHCANE SOILS. 115

and Table II gives the reaction distribution of sugar cane top and subsoils
from Follett Smith’s data (8), compared with similar padi soil data from
unpublished records in the Chemical Division.

Table II.

Reaction Dittribution of Sugar and Padi Soila.

TOPSOILS (0-12")

SUBSOILS (12—24")

Normal Reaction

Sugar

10 (0.5%)
1,487 (51%)
1,260 (44%)
124 (4%)

12 (0.5%)

Padi

Sugar

Padi

below pH 4.00 — very highly acid
pH 4.00-4.99— highly acid
pH 5.00—5.99 — markedly acid
pH 6.00—6.99 — slightly acid
above pH 7.00 — alkaline

13 07%)
53 (72%)
8 (11%)

30 (1%)

1,387 (48%)
860 (30%)
541 (19%)
75 (2%)

5 01%)
17 (39%)
14 (32%)
8(18%)

■

Total No. of Samples

2,893

The figures in Table II show that the padi topsoils have also changed from
alkaline to acid, and the fact that their subsoils are less acid than the topsoils
is further evidence of this change. On the whole the padi soils are not so acid
as the sugar soils, but these sugar soil samples include pegasse and pegassy
clay, which form about 25% of the sugar soils of this Colony. These peaty
Boils are by nature more acid than the clay soils, and padi is grown, only on
clay. However, the main point is clear, that the padi soils of the Colony are also
markedly acid, although they have not been treated with sulphate of ammonia.

The fact that the majority of padi topsoils lie between pH 5 and 6 may be
taken as an indication that the sugar soils might have reached this level of
acidity even although no sulphate of ammonia had been used. Thus the con-
tinued use of sulphate of ammonia may not have been responsible for the
initial change from alkaline to acid, but it is probably the main factor in the
increasing acidity which is seen today on the more acid soils.

The acidifying effect of sulphate of ammonia on a heavy clay grassland
soil was clearly demonstrated at Rothamsted Experiment Station (5) where
plots which had received sulphate of ammonia continuously since 1863 showed
pH values ranging from 3.8 to 4.8, the figure for unmanured plots averaging
6.8. It was found that with increasing amounts of ammonium salts the crop
yield increased, but the herbage changed from a very mixed one with many
leguminous plants into a rank growth of a few species of grasses with few or
no leguminous plants or weeds. At the Woburn Experimental Farm a similar
experiment was carried out on a sandy soil, and after continuous applications
of sulphate of ammonia barley failed completely when the pH* value dropped
to 4.6.

116 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, S.

In this investigation there is a striking difference in the degree of acidity
at which grass and barley could grow. Several species of grass were still
growing luxuriantly at pH 3.8, whereas barley failed completely at pH 4.5. A
small pot experiment with cane seedlings was set up to find whether sugar
cane would grow under highly acidic conditions. White sand was used, irri-
gated by a simple nutrient solution containing mono-calcium phosphate, sodium
nitrate, potassium chloride, magnesium sulphate and the minor elements iron,
manganese, boron, zinc and copper (6). The solution was adjusted every day
with dilute nitric acid at pH’s ranging from 7 to 2, but it was difficult to main-
tain the solution at definite pH’s, owing to lack of buffering. Nevertheless the
acidity gradient was sufficiently wide to prove the point that cane seedlings
can grow, for a time at least, in solutions of higher acidity than any natural
soil solutions. Plate I shows the seedlings, 2 — 3 months old, and it will be
seen that the seedlings at the highest acidity (pH 2.5) did not grow so well
as those in less acid solutions, but those about pH 4, which would be very
highly acidic for a soil solution, looked quite as healthy as those near neutrality
(pH 7). However, this does not mean that cane would grow in a soil of pH
2 — 3, for other factors come into play in the highly complex soil system.

The relationship between soil acidity and fertility has been summed up by
Robinson (17) as follows : “ Soil acidity cannot enter into the problem of

soil fertility as an independent factor, for it is correlated with a deficiency of
available calcium, and also, in some cases, with the presence of actively toxic
aluminium compounds. Indeed, M. Tr6nel and F. Alten have demonstrated in
culture solutions that aluminium, active below pH 5.0, acts as a specific root
poison. Further, in some cases, soil acidity may be correlated with undesirable
physical conditions. It is thus not easy to assert generally that soil acidity,
per sc, is a limiting factor. The limitation may actually be due to lack of
available calcium, the presence of active aluminium, or the prevalence of an
undesirable physical condition.”

Taking the first and last of these factors together, the fact that flood-
fallowed clay soils do not respond to dressings of limestone or slaked lime is
an indication that an absolute lack of available calcium is not the limiting
factor. On the highly acidic pegasse soils, however, dressings of 1 ton lime-
stone have given definite increases in yield, but larger dressings did not give
economic responses. This means that the addition of calcium, as well as the
correction of acidity, is important. On unflooded clay soils there was a response
to liming, and this introduces two factors — physical condition of the soil and
the supply of available calcium. Flood-fallowing has been shown by Follett
Smith (10) to improve the texture of the soil, and liming is also a well-known
method of improving soil tilth. It is obvious that on this consideration liming
could never replace flood-fallowing, and the marked benefit conferred by the
latter tends to rule out texture as a key point in this soil acidity problem.
On the other hand, analysis of soils before and after flooding showed an in-
crease in the exchangeable lime, and this may mean that flood-fallowing helps
to correct any tendency to absolute deficiency of calcium by releasing some of

ACIDITY AND u ACTIVE 99 ALUMINA IN BRITISH GUIANA SUGAR-CANE SOILS* 117

the insoluble calcium of the clay minerals. Further evidence of this is given
earlier in this section, as flooding water was found to contain i to 1J tons of
carbonate of lime per acre.

Thus the supply of available calcium may be maintained by flood-fallowing,
and economic responses on flooded clay soils will be obtained only when the
reserve of calcium has been depleted. As to how long this reserve supply of
calcium will last, we have no certain means of judging, because the amounts
removed during flood-fallowing and irrigation are difficult to measure
accurately. In a recent article. Sir John Russell (18) tells of wheat
plots at Rothamsted which have received no manure for a hundred years.
The yield fell from 20 bushels to 10 bushels per acre, but with better
cultivation in recent years (still without added manure) the yield has
risen to 24.6 bushels. One plot which was dry-fallowed in 1937 gave
39 bushels in 1938. Quoting from this paper : “ Clearly it is a very long

business waiting for crop yields to come down simply by the process of
exhausting the plant food from the soil.”

In British Guiana this process of soil exhaustion is greatly hastened by
flood-fallowing and irrigation. A soil sample from the Botanic Gardens,
analysed by Sir John Harrison, gave a total content of calcium oxide of 0,61%
which, taking 1 acre-foot of clay to weigh 2,000 tons, means that there is a
reserve of topsoil oxide of lime of 10 tons per acre, or, converting this to car-
bonate, 18 tons carbonate of lime. Of this, \ to li tons is removed in flooding
water every fourth year, apart from what is removed in the cane crops and in
irrigation water. Of course, flood-fallowing also taps the mineral reserves of
the subsoil, but even then an appreciable proportion of the lime reserve is
removed by the practice of flood-fallowing. Even so, the process of exhaustion
will take many years, and the regular application of £ to 1 ton of limestone at
planting is sufficient to prolong it indefinitely.

Thus, as far as we can judge at present, calcium deficiency and undesir-
able physical texture, due to the continued use of sulphate of ammonia, are
not likely to be serious factors on clay soils for many years. The lack
of response to liming on flood-fallowed soils, compared with the marked
response to liming on clay soils in other countries may be due to the fact that
the main effect of liming is the improvement of soil texture, and that is
achieved in this Colony by flood-fallowing.

The third factor involved in soil acidity, namely aluminium toxicity,
is examined in some detail in the next two sections.

III. “ Active ” Alumina and Soil Acidity.

Jdost aluminium compounds are insoluble and take no part in plant nutri-
tion, but it has been found by water and sand cultures that soluble aluminium
compounds, such as the sulphate, can act as specific root poisons. In normal
soils the amount of aluminium in solution is negligible in this respect,
but under some conditions aluminium toxicity becomes an important, even a
limiting, factor.

118 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 8.

This subject has been studied in considerable detail, and the rdle of
aluminium in soil infertility and toxicity is discussed in a review paper by
Hardy (11). Blair and Prince (2) studied a loam which had become so acid
(pH 4.7), owing to continued fertilisation with sulphate of ammonia, that no
ordinary farm crops would grow on it. They found that acidity per se was not
responsible for the infertility of the soil, and concluded that soluble aluminium
compounds constitute one of the causes of toxicity in soils by hindering root
development. This toxicity could be counteracted by heavy applications of
soluble phosphates, or of basic materials such as lime or basic slag. Later,
Blair and Prince (3) found that, as a soil becomes increasingly acid there is
a rise in the amount of “ active ” alumina ( Le ., alumina soluble in 0.5N acetic
acid), which may reach a toxic level. They also found that a highly acidic
soil (pH 4.07) could have its content of active alumina reduced by treatment
with limestone, acid phosphate, or basic slag, the latter being the most
effective. Ammonium salts, e.p., sulphate of ammonia, tended to increase the
amount of active alumina in the soil, apart from any acidifying effect of the
fertiliser .

In 1926 Line (13) criticised very strongly most of the previous papers
on toxic alumina in soils, and he submitted evidence that the “toxic alumin-
ium ” theory of acid soils is no longer tenable. But the contents of
“ active 99 .alumina which he gives for his experimental soils are low (up
to 66 parts per million) compared with those of soils used by other workers,
and with those of British Guiana soils given elsewhere in this paper
(up to 1,000 p.p.m.). Further, he makes no distinction between the presence
of soluble alumina and the presence of toxic amounts of soluble alumina.

In the same year, Blair (1) reported that a soil sample was received at the
New Jersey Experiment Station accompanied by the statement that “ nothing
would grow on it.” Analysis showed that it was very acid and that it contained
a high percentage of aluminium salts soluble in dilute acid. Greenhouse experi-
ments with barley showed no growth, even when nitrate of soda and muriate
of potash were added. When, however, in addition to these there wAs added
a substance with the power of rendering the aluminium compounds insoluble,
such as lime, basic slag, or even acid phosphate in excessive amount, the
barley grew luxuriantly. The interesting point is that where the acid phos-
phate was used in heavy applications without lime, the soil still remained acid
but the barley grew as well as when lime was used. Blair considers that it is
more important to put out of action the soluble aluminium compounds than to
correct the acidity.

The relationship of active alumina and soil acidity has formed the basis
of many studies related to field problems. Magistad (16) found that it was
only outside the pH range 4.7 to 8.5 that appreciable quantities of soluble
alumina occurred in the soils which he tested. Thus pH 4.7 appeared to be
$he “danger-point,” but he also found that aluminium phosphate is precipi-
tated at pH 3.9, so that the presence of large amounts of phosphate would

ACIDITY AND " ACTIVE " ALUMINA IN BRITISH GUIANA SUGAR-CANE SOILS. 110

lower the danger-point from pH 4.7 to 3.9. This explains Blair’s findings that
acid phosphate could correct the effect of alumina without raising the pH of
the soil. This was confirmed by McLean and Joffe (15), who found that
sulphate, as well as phosphate, prevented aluminium going into solution, since
it suppresses the change from colloidal to molecular dispersion.

It may be, therefore, that the use of sulphate of ammonia as a source of
nitrogen has hindered the accumulation of toxic amounts of soluble alumina,
although its acidifying action has brought the soil nearer to the danger point.
This danger-point is complicated by the presence of phosphate or sulphate; for
instance, one field with pH 4.2 might have toxic amounts of alumina present,
while another, with the same pH but more phosphate or sulphate, would have
less alumina in the soluble form.

We have, in “ active ” alumina, a toxic principle which has proved to be
of importance in other countries, and which may come into play now that the
sugar cane soils are reaching a high degree of acidity. Accordingly, a labor-
atory investigation was carried out to find the extent to which it occurs in
clay and pegasse soils, and this is reported in the next section.

IV. “Active" Alumina in Clay and Pegasse Soils.

Since aluminium toxicity seems to be a probable result of excessive acidity,
a series of determinations was carried out in order to find the content of
“active” alumina in clay and pegasse soils. The analytical method employed
was that of Burgess (4), in which the active alumina is extracted with 0.5N
acetic acid.

Table III gives the data for typical clay and pegasse sugar cane soil
profiles. Further analytical data for these profile samples appear in a report
by Follett Smith (8). The figures for active alumina are parts per million
of air-dry soil.

The figures in Table III illustrate what may be a key point in the problem
of soil acidity on the sugar lands of this Colony. It is striking that the
pegasse surface soil contains over 50. times as much active alumina as the clay
surface soil. It happens that this clay soil contains much less active alumina
than others reported below, but the general principle remains, that the pegasse
soils contain higher amounts than do the clays. The practical significance of
this is that the clay soils, compared with pegasse, are less likely to accumu-
late toxio amounts of soluble alumina, and therefore we should expect to find
the detrimental effects of acidity on pegasse much earlier than on clay — if,
indeed, the latter ever reaches the limit of tolerance for cane.

The next step was to find the effect of a change of soil reaction on the
content of active alumina. For this, composite samples of clay and pegasse
were treated with graded amounts of lime water and 0.1N sulphuric acid,
allowed to dry in the air, rewetted and dried, and then subjected to analysis.

121

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

tX. 8.

Table III.

Active Alumina in Clay and Pegasse Profiles.

Sample No.

Depth.

I “Active” A1*0
i p.p.m.

Frontland Clay . —

(Field 4 W. Sophia)

D. 636

0— 6 ins.

5.00

1). 637

6-12 „ 1

D. 638

12-18 „ i

4.98

D. 635)

18-24 ,.

6.34

D. 640

24—30 „

1 6.89

D. 642

36-42 „

7.37

Pegasse Soil —

(Field 150 W. Uitvlugt)

D. 685

0— 6 ins. !

5.61

1212

* D. 686

6-12

5.02

805

D. 687

12-18

5.20

549

D. 688

18-24

4.93

381

1). 689

24-30

4.54

120

D. 690

30-36

4.85

101

D. 691

36-42

4.93

D. 692

42-48

4,95

D. 693

48-54

5.02

D. 694

54-60

4.62

D. 695

| 60-66

4.60

D. 696

' 66-72

4.21

616

Table IV gives the relevant data, and it will be seen that the untreated clay
soil contains five times as much active alumina as the surface soil of the clay
profile in Table III. Nevertheless this amount is still much less than that in
the pegasse soil.

It is clear from Table IV that with increasing acidity there is an increase
in the content of aluminium extractable by 0.5N acetic acid. It is interesting
that in both soils there is a comparatively large increase at pH 4.7, but the
possibility of aluminium toxicity in the clay soil at that pH is much less than
in the pegasse, since the latter contains over four times as much active alumina
as the clay. While pH 4.7 seems to be, in theory, the danger-point for pegasse,
it is not possible to fix such a point without some knowledge of the tolerance
, of different cane varieties for soluble aluminium salts. In this connection
McGeorge (14') in Hawaii found a difference between varieties in tolerance for
soluble alumina, and work along this line ought to be a useful adjunct to

ACIDITY AND "ACTIVE” ALUMINA IN BRITISH GUIANA SUGAR-CANE SOILS. 121

Table IV.

Effect of Increasing Acidity on Content of Active Alumina.

Treatment.

Active A1,0 3
(p.p.m.)

Composite clay soil (Sophia).

100 gms. soil + 60 ml.

(Ca OH),

7.29

163

nntreated soil

6.77

121

100 gms. soil + 5 ml.

O. IN H,S0 4

6.53

121

» + 12 „

6.21

121

„ + 18 „

»• **

5.90

142

♦ » M + 2.)

5.64

163

ff 1* ”1"

•« M

5.15

184

„ + 55 ,,

4.70

234

„ „ + SO „

! 4.31

278

f» »f *1“ 1 0,> ft

• f if

4.04

301

Pegassr tojmil (0—1 ft.) D. 888, Uitvlugt.

115 gms. soil +345 ml.

Ca (OH),

! 5.99

648

„ „ +230 ,,

, 5.64

690

+115 „

! 5.08

794

untreated soil

4.70

961

115 gms. soil + 10 t ,

O. IN H,S0 4

4.36

961

„ ,, + 20 „

ff f»

4.25

1030

♦t m + 30 H

• f *»

4.08

1104

breeding work in this Colony. The slight increase in active alumina in the
limed clay soil (pH 7.29) recalls Magistad’s observation (16) that soluble
alumina occurs in appreciable quantities in highly alkaline soils.

V. Summary and Conclusions.

1. The sugar cane soils of British Guiana have changed from alkaline
to markedly acid in the past thirty years, and this acidity is still increasing
owing to the use of sulphate of ammonia.

* 2. The original change from alkaline to slightly acid was probably caused
by the washing out of alkaline salts of sodium and magnesium, and was not
directly due to the acidifying effect of sulphate of ammonia. Padi soils, which
have received no sulphate of ammonia, are now generally acid.

3. Cane seedlings can grow for some months in a ‘nutrient solution
which is much more acid than any known soil solution.

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

tX s.

122

4. From work in other countries it appears that the most likely effects
of excessive soil acidity are an undesirable physical condition, calcium defici-
ency, or aluminium toxicity.

5. Flood-fallowing results in a marked improvement in tilth, and it
unlikely that liming will supersede this cultural practice as regards improve-
ment of texture.

6. Absolute deficiency of calcium is not indicated at present on flood-
fallowed clay soils, as they do not respond to light dressings of limestone. On
the pegasse soils some response has been obtained to a small dressing (1 ton
per acre) of limestone, and this may be an indication of a shortage of available
calcium, since the quantity used was far from sufficient to correct the acidity.

7. There is an increase in available calcium after flood-fallowing which
means that some of the insoluble calcium of the clay minerals has been rendered
available.

8. Flooding removes appreciable quantities of salts in solution, and
results in a loss from the soil of l to 11 tons carbonate of lime per acre. This
tends to deplete the reserves of calcium, and may eventually induce calcium
deficiency. A response to small applications of limestone on flood-fallowed
clay soils would be an indication that the supply of available calcium in the soil
is not sufficient for the needs of the crop.

9. The content of “ active ” alumina in pegasse soils is high, and there
is a possibility that it may reach a toxic level. In clays the content of active
alumina is much lower.

10. With increasing soil acidity there is an increase in the amount of
active alumina, but on the clay soils this is not likely to reach a toxic level.

11. Evidence of varietal differences in tolerance of soluble alumina has
been found in Hawaii. This may account for the success of P.O.J. 2878 on
pegasse lands, as compared with D. 625 and Diamond 10. Further investiga-
tions on this line might be of value in breeding work.

12. These observations suggest that, on the heavy clay soils, the ultimate
result of increasing soil acidity would not be disastrous, as the application
of moderate dressings of limestone or slag would quickly correct the toxicity.
Nevertheless, the regular application of i to 1 ton of limestone at planting, as
recommended by this Department, would prevent, or delay indefinitely, the
adverse effects of excessive acidity. On pegasse and pegassy clays the high
content of active alumina renders it important that a regular liming programme
of at least 1 ton per acre at planting should be adopted.

References.

1. BLAIR, a. W. (1926). New Jersey Agr, Expt. Sta. Bull. 430, 1926, p. 4.

2. and Prince, A. L. (1923). Studies on the toxic properties of soilB.

k — Soil Science, Vol. 15, 1923, p. 109.

3. . (1927). The relation of soil reaction to active aluminium.— Soil

Science, Vol. 24, 1927, p. 205.

ACIDITY AND " ACTIVE ” ALUMINA IN BRITISH GUIANA SUGAR-CANE SOILS. 123

4. Bubgess, P. S. (1928). A method for the determination of “active”
alumina in acid soils. — Soil Science, Vol. 15, 1923, p. 181.

6. Ceo wt her, E. M. (1925). Studies on Soil reaction IV. The soil reaction
of continuously manured plots at Rothamsted and Woburn. — J. Agr.
Science, Vol. 15, 1925, p. 222.

6. Ellis, C. and Swaney, M.W. (1938). “Soilless Growth of Plants,”

p. 146. — Reinhold Publishing Corp., New York.

7. Follett-Smith, R. R. (1931). B.G. Dept, of Agr. Ann. Rept Chemi-

cal Division, 1931.

8. ■. (1932). B.G. Dept. Agr. Ann. Rept. Chemical Division, 1932.

9. . (1986). B.G. Dept. Agr. Ann. Rept. Chemical Division, 1936.

10. and Robinson, L. A. (1936). Flood-fallowing. — Agr. J., British

Guiana. Vol. 7, 1936, p. 227.

11. Hardy, F. (1926). The role of aluminium in soil infertility and toxicity.

— J. Agr. Science, Vol. 16, 1926, p. 616.

12. Harrison, SIR John (1908). Varieties of sugar cane and manurial

experiments in British Guiana. West Indian Bull. Vol. 9, 1908, p. 1.

13. Line, J. (1926). Aluminium and acid soils. — J. Agr. Science, Vol. 16,

1926, p. 335.

14. McGeobge, W. T. (1925). The Influence of aluminium, manganese and

iron salts upon the growth of sugar cane and their relation to the
infertility of acid island soils. — Expt. Sta. Hawaiian Sugar Planters’
Asso., Bull. 49, 1925.

16. McLean and Joffe (1927). Ann. Rept. Soils Division New Jersey
Agric. Expt Sta. 1927, p. 333.

16. Magistad, O. C. (1925). The aluminium content of the soil solution and

its relation to soil reaction and plant growth. — Soil Science, Vol. 20,
1925, p. 181.

17. ROBINSON, G. W. (1936). “Soils, their Origin, Constitution and Classi-

fication.” — 2nd edition, p. 424. Murby and Co., London.

18. Russell, Sir E. John. (1939). The trend of progress in crop produc-

tion. — Chem. & Ind. Vol. 58, 1939, p. 664.

EXPERIMENTAL CULTIVATIONS IN THE NORTH WEST

DISTRICT— 1928-1938.

E. B. MARTYN, B.A., A.I.C.T.A.,

Botanist and Plant Pathologist, Department of Agriculture, British Guiana.

INTRODUCTION.

In the year 1907, when the cultivation of rubber-producing trees held
promise of playing an important part in local agricultural practice, the Depart-
ment of Science and Agriculture decided to start an experimental station in
the North West District where rubber planting was already being carried out.
The site selected was at Hosororo, on the Aruka River, and the station was
placed in charge of an Agricultural Instructor. This Rubber Station was
maintained until 1927, by which time such changes had occurred in the rubber
market that the cultivation of the crop had been abandoned and the tapping of
the trees on the station was no longer worth while. Besides rubber trees of
varying kind, a small lime cultivation and a few odd trees of citrus and cacao,
the station carried no other crop.

In 1927 Mr. H. C. Sampson, Economic Botanist of the Royal Botanic
Gardens, Kew, visited the North West District during a tour of the Colony
and envisaged the possible extension of citrus cultivation in the district.
Shortly afterwards proposals were put forward for the introduction of settlers
into the district. The Department of Agriculture therefore decided to extend
the scope of the station to include the experimental cultivation of crops which
might prove of value and more especially to start a citrus orchard, both to
explore the possibilities of citrus culture on the few lateritic hills of the district,
of which Hosororo was representative, and to establish a source of budwood to
aid in the extension of citrus cultivation in other parts of the Colony. In
August 1928, an Agricultural Superintendent was appointed to the district and
placed in charge of the station and work was begun on the new programme.
In February 1934 the Superintendent died and since that time the station has
again been under the charge of the Agricultural Instructor of the district,
supervised since 1935 by the Government Botanist.

In 1928 the Farmers’ Association of the North West District was culti-
vating a small area of grey sand on the Wauna Creek, Koriabo River. After
the survey of the district carried out in 1929 with a view to proposed settle-*
ment, it was found desirable to experiment with the possibilities of establish-
ing permanent crops on soils of this type, which were found in much of the
area surveyed and occurred also in other parts of the Colony. As Wauna
offered the only readily accessible area on this soil type, it was taken over
from the North West District Farmers’ Association by the Department to be
run as a sub-station to Hosororo, and cleared for planting, which was begun in
1930 .

experimental cultivations in the NORTH WEST DISTRICT— 1928-1938. 125

Work has now been carried out both at -Hosororo and Wauna for ten years
and these notes form a summary of what has been done and record the various
crops that have been tried.

HOSORORO.

Description op the Soil.

Hosororo Hill is one of a series of lateritic hills, a few hundred feet in
height, which rise up like islands in the pegasse swamp that covers the North
West District near to the coast. It is on such high land that the Aboriginal
Indians find suitable sites for growing their cassava, small areas being cleared,
planted and then abandoned when one or two crops have been taken off.
Hosororo itself, having springs and a fresh water creek ending in the
fall from which the locality is named, must for centuries have been the site of
such shifting cultivation, and in places, especially on the steeper slopes, the
soil has suffered considerably from erosion, so that many areas are gravelly,
with outcropping rock and stones only a few inches below the surface. One
result of this has been that the selection of suitable areas for experimental
cultivation has resulted in a rather scattered ‘lay-out’ of the station as a whole.
The eastern end of the hill, where the station is situated, runs down into the
pegasse flat that extends from the hill foot to the Aruka River. This pegasse
area was the chief site of the former rubber cultivation. HT 1929, after com-
pleting the ‘colonisation’ survey of the North West District, the Chemist-
Ecologist examined the soils of the Hosororo Station and the following notes
are taken from his Report*.

He refers to the area which includes Hosororo as follows (loc. cit. p. 3) :
“Rising from the swamp are dykes and bosses of intrusive plutonic rocks
“ some 200-300 ft. in height. They are covered with a blanket of red lateritic
“ clay mixed with nodules of concretionary ironstone.” With regard to the
station itself, he states (loc. cit. p. 271 : “The lateritic fine silt, which occurs
“as a shallow covering to the Hosororo Hill and extends as a wide belt across
“ the centre of the station, is typical of similar areas occurring in the area
“surveyed. It contains more organic matter, more available and total phos-
“ phate, and possesses a, higher lime requirement, which differences are
“ presumably due to previous cultivation. It has already been pointed out that
“a considerable amount of erosion has taken place on the hill slopes, and at
“ many points in the area so little fine earth remains that cultivation is
“precluded.” He also points out that the pegasse soil of the ‘station, which
had been in cultivation for many years, coulu not be taken as in any
way “ typical of the virgin pegasse of the vicinity.” The average annual rain-
fall at Hosororo during the last ten years has been 106 inches.

The Crops Cultivated.

Citrus.

Varieties planted :

Oranges and Grapefruit. In 1928 an area of 2 acres was cleared on the
hill to the south west of the station, immediately beyond the creek, and planted

*The Report of a Soil Survey of an area of the North West District of British

Guiana. R. R. Pollett-Smith, Dept, of Agric. Chem. Bull. No. 1, 1930.

126 AGRICULTURAL JOURNAL OP BRITISH GUIANA. tX 8.

in June with an assortment of budded citrus varieties obtained from Trinidad.
Seven rows of twelve plants each were set out. In December of the
same year six rows were added of Marsh grapefruit, budded at the Botanic
Gardens with budwood obtained from Trinidad, and labelled ‘Botanic Gardens
Marsh’ to distinguish it from the plants budded in Trinidad.

In 1929 another 53 Marsh from the Gardens were planted in May, to fill
the original clearing, and during that year the whole citrus cultivation was
increased to ten acres. To the west of the original planting, and separated
from it by a windbreak of British Honduras Mahogany, planted at the same
time, a further clearing was made. Here, an assortment of oranges,
tangerines and Walters grapefruit, budded at the Botanic Gardens with
Trinidad budwood, were planted out in June, totalling eight rows of eight
plants each. Adjoining these also there were planted four similar rows of
Duncan grapefruit, also budded at the Gardens. In addition, another field had
been cleared to the south-west of the abovementioned area, and in this were
planted six rows of Marsh grapefruit from the Gardens — ten plants in each.
All the abovementioned plantings were on sour orange stock.

In 1980 two more rows of Duncan were adfled and from 1931 onwards the
south-west field was gradually extended and planted with a variety of citrus
including Marsh on rough lemon stock, lemons, tangelos, etc.

Limes. In addition an area of 5 acres had been cleared in 1929* on the
south-east slope of Hosororo Hill and planted, half with limes budded on sour
orange stock and half with seedling lime3. These limes were all of a local
variety established in the area, which tends to be large and rather rough-
skinned, somewhat resembling a small lemon in appearance but with a definite
lime flavour. It is too large and rough for the green lime trade, but is
satisfactory as regards yield of juice and oil. It may possibly be akin to the
Tahiti lime. The limes in the North West District however, are in general
somewhat rougher and larger than those found on the coast and it was thought
possible that these characteristics may in part be due to the locality and heavy
rainfall. In addition, therefore, there were planted two rows (24 plants) of
typical West Indian smooth-skinned limes from St. Lucia and 2 plants of a
hybrid lime from Dominica, for comparison with the local lime, and to observe
any possible effect of the locality upon them. The fruit borne by these has
however, retained the smooth appearance characteristic of the West Indian lime
and the local lime would therefore appear to be of a slightly different variety.

In 1936 a further addition was made to the lime collection at the station
consisting of twelve plants of a British Guiana (Ceylon) lime, the origin of
which was as follows. In 1932 a reference was noted in the Ceylon
Agricultural Department’s Journal to a “ British Guiana ” lime which was
being extended in cultivation there. On enquiry it was found that the
variety in question was very prolific and bore small, thin-skinned and very juicy
fruit. Samples were sent to this Department and proved quite distinct from
any fruit now known in the Colony, but the Ceylon Department reported that
seed of the variety had been obtained originally from British Guiana in 1917.

EXPERIMENTAL CULTIVATIONS IN THE NORTH WEST DISTRICT— 1928-1938. 127

Its origin is therefore rather obscure, but when the trees at Hosororo bear it
will be of interest to see how the fruit turns out in the country of its supposed
origin.

The following list summarises the budded citrus planted at the station in
1933.

Budded Grapefruit .
Marsh —
Duncan

Florida Marsh

Pernambuco

Labuan

Walters

Foster

213 plants

>»

314 plants

Budded Oranges.

St. Michael's Blood
Late Summer
Jaffa
T. H Late
Dancy Tangerine
Lue Gim Gong
Ruby

Parson Brown

Pineapple

Homosassa

Navel

Valencia

Satsuma

Grenada Orange
William Tangelo
Sampson Tangelo
New Tangelo
Sunrise Tangelo

6 plants

1 plant
4 plants
1 plant

122 plants

Budded Lemons, etc.

Ponderosa Lemon —

• Sicily Lemon —

Hybrid Lemon (Trinidad)
Succadee (Citron)

4 plants
3 „

2 „

1 plant

10 plants

128

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X. 8.

Limes — budded and seedling.

Budded Limes — local 168 plants

„ — W.I. Smooth-skinned (St. Lucia) 24 „

„ — Hybrid (Dominica) 2 „

„ — Spineless 1 plant

Seedling Limes — Local 168 plants

368 plants

The following varieties have also been established in the south-west field
subsequently :

King Orange — 5 plants

‘Pink’ Marsh grapefruit 8 „

Citropsis schweinfurthii ...... 1 plant

Swinglea glutinosa 1

Murraya exotica 1

Clement Tangelo 1

Lake Tangelo 1

Minneola Tangelo 1

Smooth-skinned lemon (Surinam) 6 plants

Large thin-skinned lime (Dominica) 8 „

23 plants.

Planting and Cultivation. All the budded citrus, with the exception of a
few trees in the south-west field on rough lemon, was on sour orange stock.
The planting distance was 25' x 25' except in the south-west field, where the
trees were spaced 30' x 30'. A few of the trees settled too low in the soil
after planting, which condition however, was easily rectified by inarching with
sour orange stock. Very little pruning was done to the young trees. It
subsequently became apparent that the only areas of good soil were at the east
end of the first field, where part of the Botanic Gardens Marsh is planted in
a ‘pocket’ on the hill-side in which the soil is fairly deep, and in the lime field.
Elsewhexe, the soil is for the most part shallow and often very gravelly, with
many outcrops of rock, and the growth of the plants has been poor — in some
cases very poor. On some of the steeper slopes contour drains were dug to
stop further erosion and the edges of these planted with Khus-khus Grass
(Anatherum zizanoides), but only on the better soil under the Botanic Gardens
Marsh was it possible to establish a cover crop — Calopogonium mucunoides.
Throughout the cultivation a certain amount of supplying was necessary,
subsequent to the original planting.

In the Botanic Gardens Marsh plot the trees made good growth, but as
they developed, it was apparent that for the vigorous growth made in this
area, they had been planted too close and also, partly owing to lack of shaping
at the outset, they had become very woody and required drastic pruning, which
was carried out in 1938 and 1939.

EXPERIMENTAL CULTIVATIONS IN THE NORTH WEST DISTRICT— 1928-1938. 129

Manurial Treatment . In 1933 rows 1-15 of the Trinidad citrus and the
Botanic Gardens Marsh in the first field were given a dressing of artificial
manures consisting of i lb. potash, 1 lb. rock phosphate, 1 lb. superphosphate
and 1 lb. sulphate of ammonia per tree.

In 1938 it was decided to give two dressings of artificials, one at mid-
year and one at the end of the year to about half of the oranges west of the
mahogany belt, and half the Duncan grapefruit and also to the miscellaneous
citrus varieties in the south-west field. Each dressing consisted of 2 lb. potash,
1 lb. superphosphate and 1 lb. sulphate of ammonia. By May 1939, the
oranges and miscellaneous citrus varieties, all of which were planted on very
poor soil, had shown some response to the treatment in increased vegetative
growth. In the case of the oranges which were on very gravelly ground, new
soil also was placed over the roots of the plants. There has as yet been no
noticeable response shown by the Duncan grapefruit, as the trees treated were
already growing quite vigorously, but the coming crop (1939-40) should
benefit. The dressings are being repeated on all these trees in 1939.
Fruiting — Production :

Oranges and Grapefruit . The Botanic Gardens Marsh bore a little fruit
in 1933 and in 1934 the trees began to come into full bearing. The 1935-36
crop was a fair one and the 1936-37 crop a very big one. In 1937-38 the crop
was less, and the 1938-39 crop was very poor, partly owing to the destruction
of blossom by the abnormal rains of 1938 and also owing to the very heavy
pruning given to the trees in that year. The grapefruit crop is from Novem-
ber to April; the orange crop begins rather earlier and is usually over by
March.

The following table shows the crops that have been obtained at Hosororo.

Table.

Orange and Grapefruit Yields at Hosororo.

1934-1935 1935-1930

1936-1937

1937-19381938-1939

Grapefruit,

Varieties from Trinidad

1,211

3.505

I 4,836

5,088

1,196

Botanic Gardens Marsh

8,382

1 12,553

1 34,640

20,314

5,302

„ „ Walters

! 45

162

1 408

494

M „ Duncan

i ' 549

1,212

! 1,434 -

1,806

S.W. field, Marsh

—

1 J» ,

_10l_

1,162

1,168

Total

9.695

1 10,685

41,017

28,406

9,966

. Oranges.

Varieties from Trinidad

7,289

4.545

11,092

8,732

2,988

Botanic Gardens Oranges

304

1^072

1,222

878

Total

7,332

4,849

12,164

9,954.

3,866

iSO AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 8.

Looking at the yields of individual trees it is found that these vary very
considerably. In the Botanic Gardens Marsh section during the 1986-87 crop
a few trees bore over 1,000 fruits, but the average per tree was only 280, since
a number of the trees on patches of poor soil bore little or nothing. Amongst
the plants from Trinidad the average crop of oranges per tree in the 1986437
crop was only 258 fruits, though a few individual trees bore six or seven
hundred fruits.

Limes. The limes bore a small crop in 1932 when 3 years old, the 2i acres
of 'seedlings’ giving 6 barrels and the 2i acres of budded plants yielding 17i
barrels, showing clearly the value of budding to give quicker bearing. Subse-
quently also the sour orange root system appeared to give better support
on the very steep hillside where the limes were planted. A number of the trees
on their own roots were blown over.

By 1934 the budded limes gave 202 barrels and the ‘seedlings’ 56 barrels,
but in 1935 the crop was a very short one, yielding only 99 and 40 barrels
respectively. In 1936 the crop was sold to the lime factory in the district; 216
barrels were obtained from budded and ‘seedling’ plants together. In 1937 the
crop was good and 400 barrels were obtained ^rom the whole field. The 1938
crop was poor, owing to damage by continual rain.

Fruiting — Quality :

Oranges and Grapefruit. As regards the quality of the fruit, it has
tended throughout to be coarse, and sometimes rather lacking in juice. The
grapefruit are large and often thick-skinned, though this latter feature was
more marked at the first bearing than latterly. It is probable that the high
rainfall is largely responsible for this coarse appearance, despite which the
fruits have a good flavour. A sample of 400 Marsh grapefruit sent to
the British Guiana Fruit and Canning Company in 1935 for trial canning gave
fairly promising results. Some of the oranges, especially the Parson Brown,
tend to bear dry fruit, though by picking this fruit early a certain amount of
juiciness is retained.

A number of the Botanic Gardens Marsh trees were found to be bearing
fruit with a good deal of seed in it, either due to the budwood used in propa-
gation or to crossing having taken place with some of the manytother varieties
of citrus in the orchard, with some of which occasional cross-pollination may
be possible. The degree of seediness may vary considerably from year to
year in individual trees but the worst trees were cut back in 1938 and top-
worked with scions from a Marsh tree of known good quality (one of the
original Trinidad plants). It was found that if the whole tree were cut bade
to a stump, scions crown grafted on to this ‘ took ’ very readily.

Chemical Analysis of the Grapefruit Cultivation. In 1935 the Chemist
analysed samples of leaf, fruit and soil from the Marsh grapefruit cultivation
at Hosororo, taking samples from healthy trees, bearing well, and also from
stunted trees, which bore little or no fruit and showed a tendency to appear

SCPWMSNTAL CULTIVATIONS IN THU NORTH WEST DISTRICT— 1928-1938. 131

chlorotic It was concluded from the leaf analyses that the “ low values
“ for total ash suggested the need for fertiliser applications. The divergent
“values for the various nutrient ratios indicate that the balance of nutrients
“ requires adjustment by correct manuring. A comparison of the values obtained
“ from the healthy and unhealthy trees indicates the value of lime in grapefruit
“nutrition.” The soil analyses showed the lime status of the good soil to be
adequate, but the poor soil to be highly acidic. In the fruit analyses the sugar-
acid ratio indicated that the quality was poorer than that of Trinidad grape-
fruit but compared very favourably with that of Puerto Rico, Florida and Texas.
The phosphate content of the fruit was also relatively low. It was therefore
decided to dress six unhealthy trees with 7 lb. limestone and 4 lb. basic slag
per tree, and to give an application of 3 lb. of superphosphate to six of the
healthy trees and note any effect on the quality of the fruit. This was dene in
the early part of 1936.

The results of these dressings were not very conclusive. Three of the
limed trees lost their chlorotic appearance, but showed no other improvement
and the remainder showed no response. The application of superphosphate
appeared to improve the yields, especially on three of the trees, but no very
noticeable change in the quality of the fruit was apparent. It may be noted
that in other cases of yellowing of the citrus trees, application of pen manure
had brought about a greener appearance. The possible effect of spraying with
?inc sulphate on these trees is now also being tested. This chlorotic appearance
is seen occasionally on the lime trees also, and may sometimes be correlated
with the fact that the trees had been planted on a very stony piece of ground.

Diseases and Pests . As regards diseases, the citrus has remained
healthy, with the exception of scab ( Elsinoe Fawcetti ), which is very trouble-
some on the sour orange stock in the nurseries. The chlorotic appearance
assumed by some of the trees is generally to be correlated with a patch of poor
and rocky soil where the plant is situated and such trees are occasionally at-
tacked by ants at the root. (Ref. also the previous paragraph). In the south-
west field the Marsh grapefruit suffered considerably during the first year or
two of their growth from the destruction of flushes of young leaves by wild
bees until their nests in the surrounding bush had been found and destroyed.
It has also been necessary to be constantly on guard against Coushi ants, and
trace and destroy their nests regularly. These insects did a good deal of dam-
age to the young plants at the outset.

General Conclusions. The following general conclusions may be drawn
from this experimental citrus cultivation :

(T) The lateritic hills of the district are well suited to citrus provided
that areas are selected in which the soil has not been exhausted by
Indian cultivation or eroded during previous clearing and that the
necessary steps are taken after planting to avoid erosion and wash-
ing away of surface soil.

♦ Divisional Reports of the Department of Agriculture for th* year 1938, q. 82,

132

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X. 8.

(2) Where vigorous growth is expected planting distances should be at
least 80' x 80' for grapefruit and 25' x 25' for oranges and card
should be taken to shape the trees well at the outset.

(3) Selection of good budwood and the avoidance of mixing too many
varieties in any one area are precautions to be taken to obviate the
occurrence of seed in ‘ seedless ' varieties. Sour orange stock appears
to be well suited to local conditions, but precautions must be taken
against * scab ’ in the nursery.

(4) Due attention must be paid to removal of Coushi ants’ nests, espe-
cially near a young plantation, and if tall forest surrounds the
orchard, a watch may have to be kept for wild bees’ nests.

(5) Although on virgin soil good crops would be obtained initially with-
out application of artificials, the trees will respond to manurial treat-
ment and this will be a necessity if the vigour of the trees is to be
maintained.

(6) The high rainfall of the district is by no means ideal for citrus cul-
tivation and tends to give too much vegetative growth and fruits
which are large and somewhat coarsp in appearance when judged by
the standards demanded in European markets. The fruit however

* is of good flavour to meet the demands of the limited local market
for fresh fruit and in addition appears to be well suited for canning
or production of concentrated fruit juices.

Finally it may be noted that the station, in addition to supplying budded
plants to citrus growers in the district, also furnishes a good number of plants
for distribution from the Botanic Gardens and during the last 3 years has
supplied 2,200 grapefruit and 2,300 orange buds for use in the Gardens'
nursery.

Avocado Pears.

Varieties planted. In addition to the citrus, 4 rows of avocado pears (44
plants in all) were planted in June 1928 and May 1929 at the west side of the
first clearing. They included grafted plants of the varieties St. Anne’s, River,
Trapp, St. Clair, Pollock and Rudder, obtained from Trinidad in 1928 and the
local varieties Martin-Sperry and R. C. Lord, together with Munis, which were
grafted at the Botanic Gardens in 1929; subsequently in 1930 two more plants
of Trapp and another of St. Anne’s were supplied from the Gardens and in
1934 two plants of Galvana and one of Nimlioh were obtained from Trinidad.

Manurial Treatment. The pears received a dressing of artificials in 1935
consisting of $ lb. potash, 2 lb. superphosphate and 1 lb. sulphate of ammonia
per plant. In 1938 they received two dressings, one at mid-year and the other
at the end of the year, of 2 lb. potash, 1 lb. superphosphate and 1 lb. sulphate
of ammonia. The crop in 1938 suffered from damage by heavy rain to the
blossom, but the backward trees do not appear to have benefited to any great
extent from the dressing.

EXPERIMENTAL CULTIVATIONS IN THE NORTH WEST DISTRICT— 1928-1938. 133

Fruiting. The pears began to bear in 1982 but have not proved satisfac-
tory, and yields have been poor, though the best quality are undoubtedly the
Pollock and Rudder varieties and St. Clair proved a good ‘carrier*. The crop
is on from July to September. Considerable damage is sometimes done to
fruit on these trees by tiger cats.

Top-working. The local variety R. C. Lord gave the strongest vegetative
growth on the very rocky soil in this part of the field, and two trees of this
have been cut back to a stump and after allowing new shoots to spring again
these have been grafted by ‘approach’ with scions of Rudder and Pollock, the
scion being kept alive in a test tube of water tied to the stock until union took
place. Attempts at cleft grafting failed.

Coffee.

In 1928 the pegasse flat at the foot of the hill was cleared of Rubber and
planted with Coffee — 10 acres being devoted to Liberian and 6 acres to other
varieties, namely C. robusta, C. de Weveri, C. excelsa and C. stenophylla.
Bananas, maize, cassava and provisions, were also planted immediately
after clearing, to shelter the young coffee. In 1929 further coffee species
were added, including abeokuta, canephora Pierre and a Uganda variety of
robusta.

All the coffee made very poor growth on the worn-out pegasse, and
by 1934 the area under Liberian had been reduced to 2 acres for topping and
pruning experiments and the other varieties were represented only by a bed of
each. Eventually all these plants were abandoned, chiefly because all efforts
to restore fertility to the worn-out pegasse had failed.

Cacao.

A small area was planted in 1929 on top of the hill with Cacao raised from
pods of two types (labelled A & B) collected by the Director of Agriculture
from trees of historical interest on the site of an old Dutch plantation
at Kumaka on the Berbice River*. The trees there represented a mixture
of Criollo and Forastero types and bore very good quality cacao. The result-
ing trees at Hosororo, 22 from type A and 15 from type B, have also borne pods
of good quality cacao, which has been used- chiefly as a seed supply for
farmers in the district. There is a certain local demand for cacao, and culti-
vation has been extended in the North West District, where up to the present
Witch Broom disease has not appeared.

Fish Poisons.

In 1928 the Black and White Haiaris, and some of the other fish poison
plants used by the Aboriginal Indians were being considered as possible sources
of insecticides, and experimental plots were planted consisting of J acre of
Black and White Haiari (known then only as species of Lonehoearpus ) under
shade, i.e., in bush which had been underbrushed. The planting distance was
3' x 3'. Smaller areas also were established of Conami ( Clibadium

* Ajrlp. Jeum. Of B.Q. II, p. 7®. 1929.

181 AQSICULTURAL JOURNAL OF BRITISH GUIANA. [X* &

eurinamenee ) , Conaparu (Euphorbia cotinoides), Daucanani (PhyUastthua
conatni ) and Yarroconalli ( Tephrosia toseicaria). An attempt to establish
Hebitchioahabu (Serjania sp.) failed.

Analysis of these plants at Rothamsted showed however that only the
Haiaris and Yarroconalli were likely to be of commercial value, and the latter
proved difficult to cultivate, requiring a lot of atttention, so that in the end
experimental cultivation was confined to the Haiaris. In 1981, another one
acre each of Black and White Haiari were established under shade and a
similar area in the open, on cleared ground. Both varieties made very good
progress in the open, though growing slowly under the shade. In 1980 the
original Haiari plot suffered some damage from a dipterous fly, and subse-
quently a leaf spot was found on all the Haiaris, especially under shade, but
it appeared to do no serious damage. The analyses made periodically however
showed a poor rotenone content (less than 3 per cent), which has been
explained latterly by the botanical identification of the Haiaris, showing them
to be two different species of Lonchocarpus (White, L. Martynii and Black,
L. chrysophyllus ) — quite distinct from the species of the Amazon basin (cuM
and barbasco) which have a high rotenone content.

In 1934 and subsequently the Haiari plots were no longer weeded and were
left to themselves. The plants in the open had made sufficiently vigorous
growth to be able to hold their own with the 'bush' plants that sprung up, but
had they been required for use in any quantity would have had to be kept
clean, as the digging out of the roots — which contain a higher proportion of
rotenone than the stems, is extremely difficult if those of the Haiari are
mingled with roots of other plants.

The trees under shade slowly found their way up towards the canopy, and
by 1938 had assumed their true liana or ‘bush rope’ habit, the climbing stems
having in many cases a diameter of 2" to 21".

A small plot of Derria elliptiea was planted recently on the laterite, but it
does not thrive there as successfully as on the clay at the Botanic Gardens.

Oil Palms.

In 1932 a selection of oil palms raised from seed obtained partly from
palms at Onderneeming and partly from selected trees in Nigeria
was planted on the pegasse flat at the hill foot, three hundred
and twelve plants in all. These palms caught well and made, good growth and
have now begun fruiting, but already some have begun dying out as their roots
get down to water and the remainder will probably suffer subsequently in the
same way.

Miscellaneous Crops.

Spices. A few trees of Nutmeg, Cinnamon and Tonka Beans were planted.
None proved markedly successful.

Citronella. The pegasse flat between the oil palms was planted with 21
acres citronella in 1934 (4' x 4') seed having been obtained from Ceylon the
previous year. The grass grew very vigorously, but the oil obtained has been

EXPERIMENTAL CULTIVATIONS IN THE NORTH WEST MSTMCT— 1928-1938. 135

of disappointingly poor quality. Recently this grass has been planted on the
hill and oil from this source has still to be sampled.

Pepper. A small plot of Black Pepper — Piper nigrum — including a
plant of the variety Balamcotta, was planted on the hill top in 1931, using
plants of Glyricidia maculata to support the pepper vines. The site proved
unsatisfactory and in 1935 the pepper was transferred to the hill foot, where
it has also given poor results.

Tung Oil. A few plants of Aleurites montana and A. fordii were planted
on the laterite in 1935. A fordii failed entirely but A. montana has grown
fairly well and began fruiting this year. It is to be extended.

Panama Hat Palm (Carludovica palmata), has been grown for some years
in a small plot on the hillside, below the station. It grows quite well, but there
is at present no demand for the fibre.

Ginger and Turmeric. The Jamaica, Canton and Dominican varieties of
ginger were grown at the Station, and also turmeric. The Dominican variety of
ginger failed but the Canton and Jamaica varieties grew fairly well on the
laterite. They have served as a source of distribution to farmers in the
district, and ginger has been cured at the station of a quality undoubtedly
better than that generally imported into the Colony. At present, however, the
price paid in Georgetown does not attract the farmers to prepare .this article
and they are satisfied with supplying the limited local market for green ginger.
Also the frequent rainfall is inimical to successful curing.

Ginger Lily. ( Hedychium coronarium). Attempts to cultivate this plant
on a plot of land by the creek, at the hill foot, have not been very successful,
since the brackish nature of the water in the creek (which is tidal) prevents
its use for irrigation, which is necessary to obtain well-grown plants of ginger
lily. The cultivation of this crop has been carried out in response to various
requests from persons abroad who are interested in the plant as a source of
fibre and require data as to costs of production and yields. Sample bales of
dried stems have been supplied to manufacturers and though analysis of the
fibre has indicated it to be of poor quality, it is possible that it could be used
in certain classes of manufacture, . It is difficult however to obtain optimum
growth of the plant under artificial conditions. In nature the plant grows
most vigorously on banks at the margin of fresh water rivers and creeks where
the base of the plant is alternately covered and exposed by the rise and fall of
the tide.

Cherimoyer. (Anona cherimolia). Attempts to grow this on the laterite
failed entirely.

Castor OU. ( Ricinus communis). Plants of this also proved unsuited to
the laterite.

Hydnocarpus anthelminticus grew moderately on the laterite.

Azadirachta indica, the Neem, was not successful.

136 < AGRICULTURAL Joxj&naL bf Sfefri&H GUiANA. tX, S.

Pineapples and Crowa Fibre were cultivated near the citrus orchard.
They came to very little, owing to the poorness of the soil. Crowa and
Malaehra eapitata were also tried on the pegasse flat, but with no success.
Ramie or China Grass ( Bohemeria nivea ) was also a failure.

British Honduras Mahogany — Swietenia maerophylla — close planted as a
windbreak in the citrus orchard, came away well and has grown fairly satisfac-
torily. The bark suffered some damage from the attacks of larvae of a species
of Hypsipyla..

Soya Beams were tried on both the laterite and the pegasse flat without
success.

Jerusalem Artichokes were grown fin 1929) with some success on the
pegasse, and small plots of onion and cabbage were planted at the same time.

Yams and Com, tried on the hill in 1929 and 1930, were not very success-
ful. The best yield of corn was at the rate of 18 bags to the acre ( @ 180 lb.
per bag = 3,240 lb. per acre) and of yams at the rate of 11,000 lb. per acre.

Fodder Crops. Elephant Grass, Uba Cane and Wynne Grass were grown
from 1928-7-1930 for distribution to farmers.

Legumes and Green Manures. Sunn Hemp and Phaseolus semi-erectus
were introduced in 1928 without success. Attempts made in 1932 to restore
some degree of fertility to the worn pegasse soils by growing green manure
crops on them failed entirely. Several legumes, including Sword Bean, were
also tried as a cover crop under the citrus, and eventually by 1935 Calopogonium
mucunoides became established in those areas where the soil had not suffered
seriously from erosion.

WAUNA.

Description of the Soil.

This area also had for long been the site of Indian cassava cultivations, the
sandy hills being oreferred to the laterite as they are generally more readily
accessible.

Follett-Smith describes the sandy hill soils, of which Wauna is representa-
tive, as follows (loc. cit. p. 23 ) . “ The soils are acid sands of low organic
“matter content overlying a slightly heavier acid subsoil which contains a
“smaller amount of organic matter. All samples are markedly deficient in lime,
“ and in both available and total phosphoric acid. The available potash supply
“ of the topsoils is fair, that of the subsoils low. The potential supply of potash
" in all cases is low.” Such soils were obviously relatively infertile and their
value largely dependent on their humus content, and the main object of the
Station was to find whether this could be maintained and any permanent crops
raised on such sites. The average rainfall at Wauna since 1933 has been 112
inches.

THE CROPS CULTIVATED.

Citrus.

Varieties planted. In 1931 four acres of citrus were planted, spaced 30 / x
80', consisting of the following :

137

EXPERIMENTAL CULTIVATIONS IN THE NORTH WEST DISTRICT— 1928-1938.

On Bough Lemon Stock —

20 Parson Brown Orange
6 Navel Orange
13 Valencia Orange
5 Dancy Tangerine
42 Marsh Grapefruit

On Sour Orange Stock —

42 Limes

45 Marsh Grapefruit

4 Navel Orange

5 Valencia Orange
12 Parson Brown Orange

3 Dancy Tangerine •

2 Succadee (Citron) Seedlings.

A certain amount of supplying was subsequently necessary. In 1933 six
Tangelo plants and five King Orange were also added, but were transplanted to
Hosororo in 1935.

Stocks. Although growth in general was poor, the rough lemon stocks
appeared rather better suited to these sandy soils than the sour orange.

Manurial Treatment. In 1933 all the citrus with the exception of the limes
received a dressing of artificial manures. 4 lb. potash, 1 lb. rock phosphate,
1 lb. superphosphate and 1 lb. sulphate of ammonia was applied to each of the
older trees and 1 lb. of a similarly proportioned mixture to the newly planted
King Oranges and Tangelos. In 1935 the grapefruit, oranges and tangerines
were again manured with i lb. potash, 2 lb. basic slag and 1 lb. sulphate of
ammonia per tree. The trees, except the limes, made very slow progress and
many were still very small even after six years’ growth.

Fruiting. By 1934 the limes were fruiting fairly well, but the other citrus
had borne little or no fruit. In 1935 a little fruit was borne, but of
poor quality and with little juice in it. By this time it had become apparent
that, at any rate by the ordinary methods of the farmer, citrus crops could
not be produced on the station, and the field was partially abandoned, weeding
being continued only around the base of each tree.

Fish Poison Plants.

In 1930 four acres were planted with Black and White Haiari spaced 3' x
3' and two acres with Yarroconalli. The former were planted half in the open
and lialf under shade, as at Hosororo. The Yarroconalli again failed to become
established.

The Haiaris fared much as at Hosororo, though the growth at Wauna was
rather better, especially in the open. The White Haiari flowered and fruited in
the open in April 1935, giving viable seed. It was at first identified as
Lonchocarpus nicou (Aubl.) DC. but later found to be a new species named

AOtacWAtJfcAL JOURNAL Of BElTiSft CrtHAMA.

tx.8.

138 '

L. Martynii *. The Black Haiari is considered to be Lonehocarpns chryso-
phyllus Klelnh, but has never flowered in cultivation. Since 1936 no weeding
has been done and the plants have been left to themselves. By 1938 those
under the trees had assumed a liane habit as at Hosororo.

Oil Palms.

In 1932 three acres were planted with oil palms raised from seed obtained
at Onderneeming and also from selected Nigerian palms — 136 plants in
all. Since 1936 little or no weeding has been carried out on this section, but
the palms have grown quite vigorously and are now beginning to bear fruit.

Coconuts.

In 1932 three acres were planted with coconuts, nuts being taken from
selected trees in Wakenaam Island an<^ the Moruca district, and 17 St. Lucia
Dwarf Red Coconuts were also put out. All these have made very slow growth.
The Dwarf Coconuts were manured in 1934 and again in 1936 with a dressing
of i lb. potash, 11 lb. sulphate of ammonia and 1 lb. superphosphate per tree.
They showed little response however, and to date only one tree has borne a few
fruits.

Miscellaneous. 1

Arabian Coffee. In 1930 one acre was planted with this crop but it proved
of no use' at all.

Wynne Grass. ( Melinis minutiflora) . A small patch of this was planted
in 1930 and has spread widely, now completely taking over the adjacent area
to an extent of several acres.

Mesquite. (Prosopis juli flora). A few plants of both a thorny and a
thornless variety of this were planted in 1933, but the sand proved too hot for
them and they failed to become established.

Cover Crops. Attempts to establish these were not successful, although
Calopogonium mucunoides made some progress under the citrus.

General Conclusions.

It is apparent that it is not possible to restore or maintain fertility from
the point of view of crop production in these sandy soils, once it has been lost,
by any methods within the economic range of the average farmer. The only
major crop that appears to make headway on this poor land is the oil palm, but
it remains to be seen whether their yields under such conditions will be worth
while. The Wynne Grass on the other hand appears to promise value both as
a cover and a forage crop, though its behaviour under grazing has not been
studied. Wauna shows very clearly the extreme importance of conserving the
humic layer in these light soils from the time of their first clearance from
forest, admittedly a speculative proposition, even under the most careful and
intensive management.

* Divisional Reports of the Department of Agriculture for the year 1937, d 81,
paragraph 6.

THE VARIETY AND FERTILISER POSITION OF THE
SUGAR INDUSTRY, V.

BY C. HOLMAN B. WILLIAMS, M.A., A.I.C.T.A., Dip. Agr.,

Sugar Agronomist and Plant Breeder,

Department of Agriculture, British Guiana.

ESTATE YIELDS.

The Managers of the Colony’s sugar estates have kindly supplied statistics
of the commercial yields obtained in 1938. Of the widely planted canes, P.O.J.
2878 was the best yielder, Diamond 10 next and D. 625 last. The data for these
varieties are condensed and combined with those of previous years in Table I,
where the weighted mean yields for the past five years are given. Since Table
I is derived from data for five years and many thousands of acres, considerable
reliance can be placed on the relative order of merit of the three canes and
there is obviously much support for the policy, generally adopted, of eliminating
D. 625 and the growing tendency to extend P.O.J. 2878 at the expense of
Diamond 10.

Table I.

Weighted Mean Yields of 96° Sugar per English Acre from the Major Varieties

Groton in British Guiana During .

1934-1938.

From land Soils

Peg ass e Soils.

P.OJ.

2878

Diamond

l . io _ ;

, D. 625

r.o.J.

2878

Diamond

D. 625

Plant

Canes

f Acres reaped:

14,457.9

j 28,670.9

25,418.8

5,143 4

4,040.3

2,572.7

Yield of sugar
^per acre, tons :

3.87 |

1 .3.59 !

3.37

3.34

, 3.50

3.50

^ Acres reaped :

8,343.2

23,945.0

i 31,901.7

3,652.7

4,003.5 1

3.937.8

First J

Ratoons |

[Yield of sugar
vper acre, tons :

3 60

3.15

3.01

3.31

2.95 i

2.82

j' Aores reaped:

3,925.7

16,4669

! 32,216.4

1,6180

2,406.2 |

3,772.9

Second i ’

Ratoons ■

Yield of sugar
^per acre, ton i :

331

302

' 2 65

2.88

2.63

2.68

Three

[Total Yield of

I |

® j

Crops

sugar per acre,
.tons:

10.78

9.76

9.03

9.53

9.14

9.00

146 AGRICULTURAL JOURNAL OP BRITISH GUIANA. * [X, 8.

VARIETAL COMPOSITION OF THE 1939 HARVESTS.

Table II is compiled from the returns supplied by the estates and shows,
together with Figure I, the relative importance, by area, of the varieties to be
harvested in 1939.

Table II.

Percentage Distribution of the Varieties to be Reaped During 1930.

Variety.

Total English
Acres in the
Colony.

Percentage
in West
Demerara.

Percentage

along

Demerara

River

Banks.

Percentage
in East
Demerara.

Percentage

Berbice.

P.O.J. 2878

28,232.36 (45.7%)

11.8

8.0

| 33.4

46.8

Diamond 10

26,864.84 (43.5%)

20.6

38.5

18.5

22.4

D. 625

4,938.37 (8.0%)

• • i

6.7

26.9

66.4

Other canes

, 1,250.73(2.0%)

36.8

46.7

2.7

13.8

Mixed

1 521.66 (0.8%)

...

, 79.9

0.3

19.8

61,807.96 (100.%)

The areas in both P.O.J. 2878 and Diamond 10 have expanded, but the
former much more rapidly and the Java cane now covers a larger area than does
the Diamond. D. 625 is disappearing rapidly and ‘mixed' areas have been
almost entirely eliminated. Table III shows the changes, in regard to the areas
under P.O.J. 2878, Diamond 10, D. 625 and ‘mixed’ only, which have taken
place in recent years.

Table III.

Comparison of Areas of D. 625, Diamond 10, P.O.J. 2878 and “Mixed” in the

Colony During Recent Years.

Variety.

Per Cent, of Total

Area in the Colony.

1934

1935

1936

1937

1938

1939

D. 625

62.5

55.4

44.6

33.0

20.6

8.0

Diamond 10

16.8

22.7

29.4

36.6

41.3

43.5

P.O.J. 2878

1.4

4.7

9.7

19.2

31.7

45.7

“Mixed”

9.5

12,6

12.7

8.8

4.0

0.8

COMMERCIAL TESTS WITH NEW VARIETIES.

From all points of view it is desirable that the varieties which show up in
the Department’s variety trials be extended and tried out on a small scale, under
commercial conditions, as rapidly as possible. This is a valuable and almost

PLATE n.

COLONY

WEST DEMERARA

EAST DEMERARA

DEMERARA RIVER BANKS

BERBICE

Fit;. I.

Relative Varietal Composition of the Cane Areas to be harvested in British

Guiana in' 1939

PLATE III.

QUANTITY

Fk.. II.

Relative Quantities and Values of Fertilisers used on British Guiana Sugar Estates m 1938.

m VAkltTY Ak& Ftfe’rlll^R POSITION OP tHE StldAft INDUSTRY, V. 141

indispensable adjunct to the experimental work and can yield much informa-
tion regarding such factors as weed control, ease of harvest, loading and mill-
ing, quality of bagasse, adaptability to various soils, etc. It is recognised that
the establishment of odd fields of almost unknown varieties and the upkeep of
their records involve a considerable amount of trouble, some risk of a slightly
reduced yield, and, possibly, certain additional expense, but it is in the interests
of all concerned that each estate bear a portion of the burden. While some
are still hesitant, it is gratifying to record that most Managers have now
initiated some work of this nature. In consequence, an increased volume of
information from this source may be expected in future. In the meantime, the
following notes, culled from the reports of pioneers in this line, will be
of interest.

D. 885/18

This cane has been tried at Pin. Skeldon in three fields planted, respec-
tively, in 1933, 1934 and 1935. The total area involved was about 25 acres,
and the average yields of sugar per acre were : —

Plants.

First

Ratoons.

Second

Ratoons.

Third

Ratoons.

General

Average.

Tons sugar per acre

3.96

3.73

3.14

2.85

3.42

At Pin. Rose Hall, 2.6 acres of second ratoons averaged 2.48 tons of sugar
per acre in 1933, and, in 1934, 5.44 acres of third ratoons averaged 3.19 tons.

A quarter of an acre was planted at Pin. Blairmont in 1934 but the 're-
turns were not encouraging.

This seedling has been repeatedly tried at Pin. Versailles and has given
satisfactory yields there on the unkindly pegassy clay. Indeed, the Manager
recently reported : “ D. 602/22, I consider worthy of extending on any land."

At Pin. Skeldon, three acres of third ratoons averaged 3.17 tons of sugar
per acre in 1936, and four acres of first ratoons averaged 3.57 tons of sugar per
acre in 1934.

At PJn. Blairmont, yields from a few small patches (half to one and a half
acres) have not been impressive.

143

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

tX 3.

D. 927/22

An eleven-acre field has been carried through a four-crop cycle at Pin. Port
Mourant. The juice purities were somewhat low, but, as will be seen below,
yields were quite satisfactory : —

Plants,

First

Ratoons.

Second

Ratoons.

Third

Ratoons.

General

Average.

Tons sugar per acre

3.36

3.62

4.24

3.71

3.73

D. 11/28

This seedling has been tested at Pin. Skeldon and, to a lesser extent, at
Pin. Port Mourant. The average yields from 13.4 acres of plants and 14.7 of
first ratoons were :

Plants. FirBt Ratoon®.

Tons Sugar per acre

3.58

3.39

D. 49/30

Tried at Pins. Providence (Berbice and Demerara) and Skeldon, this seed-
ling averaged 4.56 tons sugar per acre from a total of 11.5 acres of plant
canes. At Pin. Skeldon, 4.5 acres of first ratoons yielded 3.58 tons sugar per
acre, but at Pin. Providence (Berbice) a small patch (1.3 acres) of first
ratoons only averaged 1.18 tons sugar per acre. In these tests the cane was
generally of high quality.

D. 66/30

A considerable number of tests with this variety are reported from Pins.
Skeldon, Port Mourant, Albion, Providence (Berbice and Demerara), Blairmont,
Bath, Cane Grove, La Bonne Intention, Diamond, Wales and Versailles. It
appears to thrive at Skeldon where it has averaged 5.09 tons sugar per acre
from 40.5 acres of plants and 3.80 tons from 22 acres of first ratoons. Good
plant cane results have been secured at Diamond, Providence (Demerara) and
Wales, but the data from other points are not encouraging and the first ratoons
at Providence (Berbice), Cane Grove and Wales were disappointing.

D. 75/30

At Pin. Leonora this cane averaged 4.95 tons sugar per acre from a 2.6
acre plot. The cane was of good quality.

TBS VAB1STT AND FERTILISER POSITION OF THB SUGAR INDUSTRY, V. 143

Co. 218

Pins. Skeldon, Albion, Providence (Berbice), Blairmont, Cane Grove and
Lusignan have been testing this cane. On 33.6 acres of plant canes it averaged
3.48 tons sugar per acre, and on 30.1 acres of first ratoons it averaged 3.27
tons. At Cane Grove, 8.0 acres of second ratoons yielded 2.29 tons of sugar
per acre.

FERTILISERS IN 1938.

In Table IV., the fertiliser imports for 1938 are compared with those of
recent years, the data being adapted from the Reports of the Comptroller
of Customs.

The quantities imported and the expenditure on all groups of fertilisers
fell, as compared with 1937, a record year. With the quota restrictions fol-
lowing the international sugar agreements, this was to be expected.

The estates have kindly supplied details as to the various manures used
in 1938, and the data for 1936 to 1938 are summarised in Table V. Figure II
is a graphical presentation of the 1938 returns. It should be noted that pul-
verised limestone has gradually replaced lime and that the imports of super-
phosphate are declining steadily.

144

AGRICULTURAL JOURNAL 07 BRITISH GUIANA,

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CATALOGUE OF THE LEPIDOPTERA RHOPALOCERA
(BUTTERFLIES) OF BRITISH GUIANA— ( Contd.)

ARTHUR HALL, F.R. Ent. S.

242. Euselasia euphaes.

(1854).

Eurygona euphaes, Hewitson, Ex. Butt. I, Eurygona t. 4, f. 38-40
Anna!.

243. Euselasia arbas euoras.

Euiygona euoras, Hewitson, Ex. Butt. I, Eurygona t. 4, f. 38-40.
(1854).

Potaro River.

244. Euselasia lisias.

Papilio lisias, Cramer, Pap. Ex. II, t. 152, F, G (1779).

Carimang River; Quonga; Annai; Nappi, Kpnuku Mts.'

245. Euselasia gelanor. '

'Papilio gelanor, Cramer, Pap. Ex. IV, t. 336, C, D (1782).

Carimang River; Annai; Quonga; Mt. Roraima.

246. Euselasia crotopus.

Papilio crotopus, Cramer, Pap. Ex. IV, t. 336, E. F., 390, G, H. (1782).
Carimang River; Mabaruma.

247. Euselasia labdacus.

Papilio labdacus, Cramer, Pap. Ex. IV, t. 336, G, H. (1782).

248. Euselasia eugeon.

Eurygona eugeon, Hewitson, Ex. Butt. I, Eurygona t. 7, f. 62 (1856).
Omai; Quonga.

249. Euselasia eurypus.

Eurygona euboea, Hewitson, Ex. Butt. I, Eurygona t. 1, f. 4, 6 (1852).
Carimang River.

250. Euselasia cheles.

Eurygona cheles, Godman & Salvin, Ann. Mag. Nat. Hist. (6), IV., p.
366 (1889).

Omai; Quonga.

251. Euselasia euboea.

Eurygona euboea, Hewitson, Ex. Butt. I , Eurygona 1. 1, f. 4, 5 (1852).
Annai.

252. Euselasia felor.

Eurygona pelor, Hewitson, Ex. Butt. I, Eurygona t. 1, f. 1-3 (1862).

Annai,

CATALOGUE OF THE LEPIDOPTERA BHOPALOCERA OF BRITISH GUIANA. 147

253. Euselasia teleclus.

Papilio teleclus, Stoll, Suppl. Cram. t. 5, f. 4, 4E (1787).

Demerara River; Carimang River; Potaro River; Mt. Roraima.

254. Euselasia urites.

Eurygona urites, Hewitson, Ex. Butt. I, Eurygona t. 2, f. 19 (1852).
Mt. Roraima.

255. Methonella CECILIA.

Papilio cecilia, Cramer, Pap. Ex. II, t. 159, D, E (1779).

Annai; Quonga; Carimang River; Upper New River, (J. G. Myers, Dec.
1935).

256. Helicopis cupido.

Papilio cupido, Linnaeus, Syst. Nat. I, p. 482, n. 145 (1758).

Locally abundant in swampy places under the sea or at the mouths of rivers.
It is found in colonies amongst the tall plants of the mucca-mucca
( Montrichardia aculeata) upon which the larva feeds. The butterflies settle
on the under surface of the leaves with the wings closed and have a very feeble
flight.

257. Helicopis lindeni.

H. lindeni, Grote, Bull. Buff. Soc. II, p. 108, t. 2 (1874).

This is usually considered an aberrant or seasonal form of H. cupido but
in December, 1929, I took lindeni at Craig Village near Georgetown and cupido
at Parika on successive days, each form being constant and common in its
locality. This seems to suggest that lindeni is either a separate species or
else a good subspecies of rather remarkable distribution.

258. Helicopis endymion.

Papilio endymion, Cramer, Pap. Ex. Ill, t. 244, C, D (1782).
Mabaruma. (Rare). Demerara River.

Sub-family ERYCININAE.

259. Eurybia nicaeus.

Papilio nicaeus, Fabricius, Syst. Ent. p. .482, n. 175 f 1775) .

Bartica; Quonga; Kaieteur Falls.

260. Eurybia dardus.

Papilio dardus, Fabricius, Mant. Ins. II, p. 230, n. 324 (1787).
Demerara River; Mt. Roraima.

261. Eurybia lamia.

Papilio lamia, Cramer, Pap. Ex. II, t. 150, C (1779).

A single specimen from Bartica in the British Museum.

262. Eurybia haliemede.

Limnas sub til is halimede, Hubner, Samml. Ex. Schmett. (1806-16).
Potaro River (Coll. Kaye).

263. Mesosemia steli.

M. steli, Hewitson, Ex Butt. II, Mesosemia t. 2, f. 13 (1858).

Anna],

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AGRICULTURAL JOURNAL OF BRITISH GUIANA.

CX, 3.

264. Mesosemia eumene.

Papilio eumene, Cramer, Pap. Ex. I, t. 92, P, G (1779).

Demerara; Bartica; Carimang River; Kaieteur Falls; Mt. Roraima.

265. Mesosemia sirenia.

M. sirenia, Stichel, Berl. Ent. Zeit. 1904, p. 14.

Takutu.

266. Mesosemia menoetes.

M. menoetes, Hewitson, Ex. Butt. II, Mesosemia t. 6, f. 56-58 (1869).
Annai; Quonga; Mt. Roraima. The specimens do not seem to be quite
typical.

267. Mesosemia phace.

M. phace, Godman, Trans. Ent. Soc. 1903, p. 529, t. 20, f. 1.

Described from Mt. Roraima. Also from Quonga and Demerara River.

268. Mesosemia ibycus.

M. ibycus, Hewitson, Ex. Butt. II, Mesosemia t. 7, f. 68, 69 (1860) .
Demerara ; Bartica ; Parika ; Carimang River ; Kaieteur Falls ; Mt. Roraima.
One of the commonest species. '

269. Mesosemia cippus.

'M. cippus, Hewitson, Ex. Butt. II, Mesosemia, t. 6, f. 48, 49 (1859).
Demerara; Bartica; Carimang River; Kaieteur Falls; Mabaruma.

270. Mesosemia sylvina.

M. sylvina, Bates, Journ. Linn. Soc. Zool. IX p. 372 (1867).

Annai; Carimang River.

271. Mesosemia nina.

Papilio nina, Herbst, Nature. Schmett. IX, p. 30, t. 233, f. 1, 2 (1798) .
Carimang.

272. Mesosemia capaneus.

Papilio capaneus, Cramer, Pap. Ex. Ill, t. 236, D (1782).

Demerara River; Carimang River; Garraway Stream; Kuturi River.

273. Mesosemia metope.

Jlf. metope, Hewitson, Ex. Butt. II, Mesosemia t. 7, f. 64, 65 (1860).
Annai; Carimang River; Potaro River.

274. Mesosemia philocles.

Papilio philocles, Linnaeus, Syst. Nat. I, p. 483, n. 166 (1758).
Demerara River; Quonga; Mabaruma; Kaieteur Falls; Mt. Roraima.
A common species.

275. Mesosemia coea.

M. coea. Httbner, Verz. hek. Schmett. p- 21, n. 146, (1816).

Demerara River; Berbice; Takutu; Mt. Roraima.

276. Mesosemia melaene.

M. melaene, Hewitson, Ex. Butt. II, Mesosemia t 5, f. 54, 55 (1859).
Bartica; Kaieteur Falls.

CATALOGUE OF THE LEPIDOPTERA RHOFALOCERA OF BRITISH GUIANA. 149

277. Mesosemia pinguilenta.

M. pinguilenta Stichel, Deutsch. Ent. Zeit. 1905, p. 671.

Type in the British Museum from the Carimang River. Perhaps only
another form of M. melaene.

278. Mesosemia methion.

M. methion, Hewitson, Ex. Butt. II, Mesosemia t. 8, f. 76 (1860).
Quonga; Mt. Roraima.

279. Mesosemia maera.

M. maera, Hewitson, Ex. Butt. V, Mesosemia t. 12, f. 114, 115 (1873).
Bartica; Quonga; Potaro River; Carimang River; Mt. Roraima.

280. Mesosemia machaera.

M. machaera, Hewitson, Ex. Butt. II, Mesosemia, t., 8 f. 70, 71 (1860).
Carimang River; Mabaruma; Mt. Roraima.

281. Mesosemia magete.

M. magete, Hewitson, Ex. Butt. II, Mesosemia, t. 8, f. 72 (1860).
Carimang River; Kaieteur Falls; Mt. Roraima.

282. Mesosemia araeostolya.

M. araeostolya, Stichel, Deutsch. Ent. Zeit. 1915, p. 682, t. 21, f. 21.
Type in the British Museum from “ British Guiana ”.

283. Mesosemia thymetus.

Papilio thymetus, Cramer, Pap. Ex. II, t. 148, G (1779).

Annai; Carimang River.

284. Mesosemia ore as.

M. oreas, Stitchel, Deutsch. Ent. Zeit. 1915, p. 687.

Takutu.

285. DlOPTHALMA PHILEMON.

Papilio philemon, Cramer, Pap. Ex. I, t. 22, G, H (1775).

Mt. Roraima.

286. DlOPTHALMA IPHIAS.

D. iphias, Stichel, Berl. Ent. Zeit. 1909, p. 274.

Annai; Carimang River; Mt. Roraima.

287. Diotthalma hyphaea.

Papilio hyphaea, Cramer, Pap. Ex. I, t. 92 C (1779).

Common in most forest districts.

288. PEROPTHALMA TULLIUS.

Papilio tullius, Fabricius, Mant. Ins. II, p. 34, n. 359 (1787).

Parfka; Kaieteur Falls. Common where found.

289. Hyphilaria nicias.

Papilio nicias, Stoll, Suppl. Cram. t. 13, f. 3 (1790).

Carimang River.

290. Hyphilaria orsedice.

H. orsedice, Godman, Trans. Ent. Soc. 1903, p. 531, t. 20, f. 5. Mt.
Roraima; Kaieteur Falls.

rx, 3.

150 AGRICULTURAL JOURNAL OF BRITISH GUIANA.

291. Eunogyra SATRYUS.

E. satyrua, Westwood, Gen. Diurn. Lep. p. 461, n. 1, note, t. 72,
f. 11 (1861).

Bartica; Quonga; Takutu; Carimang River; Kaieteur Falls.

292. Cremna actoris.

Papilio acioris, Cramer, Pap. Ex. I, t. 93 D (1779).

Quonga; Carimang River; Mt. Roraima.

293. Napaea eucharila.

Cremna eucharila, Bates, Trans. Ent. Soc. 1867, p. 643 (1867).
Demerara; Carimang River.

294. Napaea beltiana.

N. beltiana, Godman, Trans. Ent. Soc. 1903, p. 641.

Demerara.

296. Napaea orpheus.

Cremna orpheus, Doubleday & Hewitson, Gen. Diurn. Lep. t. 71.
f. 8 (1851).

Berbice.

296. Napea sylva.

Char is sylva, Moschler, Verh. Zool. — Bot. Ges. Wien. XXVI p 304
t, 3, f. 6 (1876).

Potaro River (Coll. Kaye).

297. Alesa AMESIS.

Papilio amesis. Cramer, Pap. Ex. II, t. 104, F (1779).

Demerara; Carimang River; Quonga. Sometimes common.

298. Mimocastnia rothschildi.

M. rothschildi, Seitz, Macrolep. V, p. 652, t. 127, A (1916).

This fine species is only known from the Demerara River where it is
extremely rare.

299. Themone PAIS.

Helironis vats RuWr. Samml. Ex. Schmett. C J 8 1 6 41).

Annai; Mt. Roraima; Nappi; Kanuku Mts. (J. G. Myers, 18/12/35).

300. Ithomiola floralis.

7. floralis, Felder, Reise Nov. Lep. II, p. 311, n. 422 (1865).
Carimang River; Kaieteur Falls.

301. Pheles heliconides.

P. heliconides, Herrich-Schaeffer, Ex. Schmett. p. 277, f. 30 (1853’)
Carimang River.

302. Isapis agyrtus.

Papilio agyrtus, Cramer, Pap. Ex. II, t. 123, B, C (1779).

Demerara River; Annai; Carimang River.

Vl03. Panara phereclus.

Papjlio phereclus, Linnaeus, Syst. Nat. I, p. 484, n. 169 (17581
Quonga; Annai; Mt. Roraima.

CATALOGUE OP THE LEPIDOPTEBA BHOPALOCEBA OP BRITISH GUIANA. 151

RlODINA LYSIPPUS.

Papilio lysippus, Linnaeus, Syst. Nat. I, p. 485, n. 160 (1758).
Annai; Takutu; Kaieteur Falls; Mt. Roraima. A rather common species.

305. Lymnas melander.

Papilio melander, Cramer, Pap. Ex. IV, t. 336, A. B (1782).

Carimang River.

306. Lymnas j abbas.

Papilio jarbas, Fabricius, Mant. Ins. II, p. 83, n. 749 (1787).
Quonga.

307. Lymnas ubia.

L. ubia, Felder, Reise Nov. Lep. II, p. 303, n. 408 (1865).

Annai. The British Museum also contains two specimens from Quonga in
which the band is white and the red spots are absent above. It is uncertain
whether this is a variety or a different species.

308. Lymnas thyatira.

L. thyatira, Hewitson, Ex. Butt. I, Limnas t. 1, f. 6 (1852).

Quonga.

309. Syrmatia dorilas.

Papilio dorilas, Cramer, Pap. Ex. I, t. 47, C (1779).

Annai.

310. Zeonia faunus.

Papilio faumis, Fabricius, Syst. Ent. p. 532, n. 380 (1775).

Potaro River (Coll. Kaye).

311. Zeonia batesii.

Z. batesii, Saunders, Trans. Ent. Soc. 1859, p. 97, t. 10, f. 3, 4 (1859).
A pair from Annai in the British Museum.

312. Diorhina arcius.

Papilio arcius, Johansen, Amoen. Acad. VI, p. 409, n. 79 (1764).
Kaieteur Falls. I took one specimen at sugar, the only instance in my
experience of a member of this family coming to the bait.

313. Diorhina periander.

Papilio periander, Cramer, Pap. Ex. II, t.’ 188, C (1779).

Annai; Carimang River; Mt. Roraima.

314. Ancylurus aulestes.

Papilio aulestes, Cramer, Pap. Ex. II, t. 128, G (1779).

Annai; Bartioa; Carimang River; Kaieteur Falls; Mt. Roraima. Both
sexes are very variable and the varieties have received a number of names.

315. Anqylurus tedea.

Papilio tedea, Cramer, Pap. Ex. II, t. 102, A (1779).

Demerara; Quonga.

316. Cyrenia martia.

C. martia, Westwood, Gen. Diurn. Lep. p. 434, t. 72, f. 2 (1851).

Quonga.

152 , AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 3.

317. NOTHEME EUMEUS.

Papilio eumeus, Fabricius, Spec. Ins. II, p. 63, n. 280 (1781).

Omai.

318. Esthemopsis aeolia.

E. aeolia, Bates, Journ. Linn. Soc. IX, p. 380 (1868).

Quonga.

319. Esthemopsis sericina.

Pseudopheles sericina, Bates, Trans. Ent. Soc. 1867, p. 544.

Potaro River (Coll. Kaye).

320. Mesene phareus.

Papilio phareus, Cramer, Pap. Kx. II, t. 170, C (1779).

Bartica; Annai; Quonga; Carimang River; Upper Corentyne. A very
variable species. The larva, according to Kaye, lives upon Paullina pinmta.

321. Mesene bomilcar.

Papilio bomilcar, Stoll, Suppl. Cram. t. 39, f. 3 (1790).

Bartica.

322. Mesene epaphus.

Papilio epaphus, Cramer, Pap. Ex. IV, 4. 335, D, E (1782).

Annai.

323. Mesene nola.

M. nola, Herrich-Schaeffer, Ex. Schmett. f. 23, (1852?).

Annai; Quonga.

324. Mesene pyrrha.

M. pyrrha, Bates, Journ. Linn. Soc. Zool. IX, p. 389 (1868).

Annai. The last three are very likely all forms of one species.

325. Phaenochitonia cingulus.

Papilio cingulus, Stoll, Suppl. Cram. t. 13, f. 4, 4D (1790).

Carimang River.

326. Phaenochitonia aerope.

Poeotis aerope, Doubleday & Hewitson, Gen. Diurn. Lep. t. 71, f. 2
(1851).

Annai.

327. Phaenochitonia pyrsodes.

Mesene pyrsodes, Bates, Journ. Linn. Soc. Zool, IX, p. 386 (1868).
Kamakusa.

328. Phaenochitonia sagaris.

Papilio sagaris, Cramer, Pap. Ex. I, t. 83, D (1779).

. Potaro River; Mt. Roraima.

329. Cricosoma irrorata.

% C. irrorata, Godman, Trans. Ent. Soc. 1903, p. 540, t. 22, f. 6.

Carimang River; Kaieteur Falls.

CATALOGUE OP THE LEPIDOPTEBA EHOPALOCEBA OP BRITISH GUIANA. 153

330. CBICOSOMA HIPPEA.

Symmachia hippea, Herrich-Schaeffer, Ex. Schmett. f. 39. 40 (1863?).
Demerara River; Carimang River; Potaro Road; Kaieteur Falls.

331. Pachythone lateritia.

P. lateritia, Bates, Journ. Linn. Soc. Zool. IX, p. 390 (1868).

Annai.

332. Symmachia amazonica.

S. amazonica, Bates, Journ. Linn. Soc. Zool. IX, p. 193 (1868).
Quonga.

333. Argyrogramma venilia.

Chartis venilia, Bates, Journ. Linn. Soc. Zool. IX, p. 393 (1868).

Mt. Roraima.

334. Argyrogramma trochila.

Baeoti8 trochila, Westwood, Gen. Diurn. Lep. p. 451, n. 10. note
(1861).

Carimang River.

335. Anteros formosus.

Papilio formosus, Cramer, Pap. Ex. II, t. 118, G (1779).

Annai.

336. Anteros violetta.

A. violetta, spec. nov.

Description. — Size and shape much as in A. formosus but hind wings
more dentate and having a tuft of long hairs at the anal angle. Upperside
of both wings blackish brown with a faint bluish tinge; fore wings with a
large translucent white spot placed transversely in cellule 2. Underside :
Fore wings marked much as in Sarota gyas but the large white discal spot is
present as above, the inner of the two metallic blue-green submarginal stripes
of gyas is absent and there is a triangular white spot below the base of costa.
Hind wings also marked much as in Sarota gyas but the actual base is white
and the black dots in the central area are arranged in three irregular series,
the middle ones dusted with metallic scales; two metallic blu^-green sub-
marginal lines and a broad yellow marginal stripe as in S. gyas. Legs densely
hairy.

Type from King Frederick William Falls, Upper Corentyne. (G. A.
Hudson, March 1936. This is a rather remarkable species resembling A.
ferviosuf above and Sarota gyas beneath. A second specimen with an illegible
locality label is also in the British Museum.

887. Sarota chrysus.

PapUio chrysus, Cramer, Pap. Ex. IV, t. 380, D, E. (1782).

Carimang River.

[X, 3.

f5fc AGRICULTURAL JOURNAL OP BRITISH GUIANA.

338. SAROTA GYAS.

Papilio gyas, Cramer, Pap. Ex. I, t. 28, F, G (1775).

Kaieteur Falla, Kuturi Sources. One of the smallest of all South
American butterflies.

339. Sarota acanthoides.

Nymphidium acanthoides, Herrich-Schaeffer, Ex. Schmett. f. 49, 50
(1853?).

Carimang River.

340. Ourocnemis axioohus.

Anteros axiochns, Hewitson, Ex. Butt. IV, Anteros t. 1, f. 1, 2 (1867)
King Frederick William Falls, Upper Corentyne River (G. A. Hudson).

341. Charis anius.

Papilio am us, Cramer, Pap. Ex. I, t. 92, B (1779).

Quonga; Bartica; Carimang River; Kaieteur Falls; Mt. Roraima. A
common species.

342. Charis cleonus.

Papilio cleonus, Cramer, Pap. Ex. IV, t. 380, H, I (1782).

Demerara; Carimang River; Kaieteur FaHs; Mt. Roraima. Also rather
common.

343. CHARIS zama.

C. zama, Bates, Journ. Linn. Soc. Zool. IX, p. 392 (1868).

Annai.

344. Charis argyrodines.

C. argyrodines, Bates, Ent. Mo. Mag. Ill, p. 154, n. 112 (1866;.

A very common species in all wooded places.

345. Amarynthis meneria.

Papilio meneiia, Cramer, Pap. Ex. I, t. 94, D, E (1779).

Potaro River; Mabaruma.

346. Emesis lucinda.

Papilio lucinda, Cramer, Pap. Ex. I, t. 1, E, F. (1775).

Parika; Carimang River; Takutu.

347. Emesis mandana.

Papilio mandana, Cramer, Pap. Ex. Ill, t. 271, E, F. (1782).

Quonga; Demerara River; Mabali.

348. Emesis ovidius.

Hesperia ovidius, Fabricius, Ent. Syst. Ill, (1), p. 320, n. 212 (1793).
Demerara (G. Rod way).

349. Emesis progne.

E. progne, Godman, Trans. Ent. Soc, 1903, p. 637, t. 21, f. 10.

Potaro River (Coll. W. J. Kaye).

350. Parnes piiilotes.

' P. pkilotes, Westwood, Gen. Diurn. Lep. p. 464 (1851).

Annai; Quonga; Carimang River; Mt. Roraima.

CATALOGUE OP THE LEPIDOPTERA RHOPALOCEBA OP BRITISH GUIANA. 155

851. Hamearis EPULUS.

Papilio epulus, Cramer, Pap. Ex. I, t. 50, C, D (1779).

Bartica; Demerara. Unlike most members of the family the species oj
this genus frequent open weedy places, fly close to the ground and settle with
the wings closed.

352. Metacharis LUCIUS.

Hesperia Indus, Fabricius, Ent. Syst. Ill, (1), p. 319, n. 209 (1793)
Demerara River; Annai; Carimang River; Mabaruma.

353. LEMONIAS RHODOPE.

L. rhodope, Hewitson, Ex. Butt. I, Lemonias, t. 1, f. 6, 7 (1853).
Potaro River.

345. Lemonias zeanger.

Papilio zeanger, Stoll, Suppl. Cram. t. 37, f. 2, 2b (1790).

Annai.

356. Lemonias porthaon.

Papilio porthaon, Dalman, Anal. Ent. p. 46 (1823).

Carimang River.

356. Lemonias fannia.

L. fannia, Godman, Trans. Ent. Soc. 1903, p. 545, t. 23, f. 4.

Annai. Only the type specimen known.

357. Lemonias cerealis.

L. cerealis, Hewitson, Ex. Butt. Ill, Lemonias, t. 4, f. 37 (1863).
Carimang River.

358. Lemonias nomia.

L. nomia, Godman, Trans. Ent. Soc. 1903, p. 544.

Annai.

359. Lemonias emylius.

Papilio emylius, Cramer, Pap. Ex. I, t, 66, G, II (1779).

The commonest species of the genus. Generally to be found in all forests
and wooded places.

360. LEMONIAS LUCIANUS.

Hesperia ludanus, Fabricius, Ent. Syst. Ill, (1), p. 313, n. 185 (1793).
Annai; Quonga.

361. Lemonias lyncestes.

' L. lyncestes, Hewitson, Ex. Butt. V. Lemonias, L 50, 51 (1874).
Kaieteur Falls (A. Hall).

362. Echenais tinea.

Calydna tinea, Bates, Journ. Linn. Soc Zool, IX, p. 394 (1868).
Kaieteur Falls.

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AGRICULTURAL JOURNAL OF BRITISH GUIANA.

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868. ECHBNAIS ARISTUS.

Papilio aristus, Stoll, Suppl. Cram. t. 39, f. 4, 4C (1787;.

Bartica; Kaieteur Falls; Mabaruma. Rather common.

364. Echenais hubneri.

Lemonias hilbneri, Butler, Journ. Linn. Soc. Zool. IX, p. 214, t. 6, f.'
4, 6 (1867).

Bartica; Carimang River.

366. Echenais leucocyana.

E. leucocyana, Hiibner, Zutr. Ex. Schmett. f. 915, 916 (1837).

Annai.

366. Echenais penthea.

Papilio penthea, Cramer, Pap. Ex. II, t. 143, E (1779).

Bartica; Carimang River; Kaieteur Falls: Mabaruma. A fairly common
species.

367. Echenais annulifera.

Lemonias annulifera, Godman, Trans. Ent. Soc. 1903, p. 642, t. 22,
f. 12.

Described from Quonga and only found elsewhere on the Rio Madeira.

368. Echenais aemulius.

Hesperia aemulius, Fabricius, Ent. Syst. Ill, (1), p. 322, n. 219,
(1793).

Mt. Roraima.

369. Echenais zerua.

Lemonias zerua, Hewitson, Ex. Butt. V, Lemonias, t. 6, f. 44, 46 (1872)
Mt. Roraima.

370. Nymphidium tytia.

Papilio tytia, Cramer, Pap. Ex. II, t. 121, C, D (1779).

Demerara River (G. Rodway).

371. Nymphidium orestes.

Papilio orestes, Cramer, Pap. Ex. Ill, t. 282, A, B (1782).
Nymphidium arche, Hewitson, Ex. Butt. Ill, Nymphidium t, 2, f. 10
(1865).

Demerara River; Potaro River; Carimang River; Mabaruma. According
to Stichel this species is dimorphic, the females of orestes having the bands
yellow whilst in arche they are white. Both forms are found together.

872. Nymphidium abaris.

Papilio abaris, Cramer, Pap. Ex. I, t. 93, C (1779).

Demerara; Potaro River; Carimang River; Takutu.

973. Nymphidium gela.

N. gela, Hewitson, Ex. Butt. I, Nymphidium, t. 1, f. 9 (1862).
Carimang River.

CATALOGUE OF THE LEPIDOPTEBA RHOPALOCERA OF BRITISH GUIANA. 157

374. Nymphidium phylleus.

Papilio phylleus, Cramer, Pap. Ex. I, t. 63, D, E (1779).

Demerara (G. Rodway).

375. Nymphidium pelops.

Papilio pelops, Cramer, Pap. Ex. II, t 170, F (1779).

Demerara River.

376. Nymphidium regulus.

Hesperia regulus, Fabricius, Ent. Syst. Ill, (1), p. 318, n. 205 (1795).
Annai.

377. Nymphidium lamis.

Papilio lands, Cramer, Pap. Ex. IV, t. 335, F, G (1782).

Annai; Quonga; Carimang River.

378. Nymphidium satyroides.

Nymula satyroides, Lathy, Ann. Mag. Nat. Hist. (10), IX, p. 73 (1932).
Type from "British Guiana” (Parish) in the British Museum.

379. Nymphidium molpe.

Limnas subtilis molpe, Hiibner, Samml. Ex. Schmett. (1806-16).
Parika.

380. Nymphidium azanoides.

N. azanoides, Butler, Ent. Mo. Mag. Ill, p. 221 (1867).

Annai; Carimang River; Kaieteur Falls.

381. Nymphidium fulminans.

N. fulminans, Bates, Journ. Linn. Soc. Zool. IX, p. 400 (1868).

382. Nymphidium lisimon.

Papilio lisimon, Stoll, Suppl. Cram. t. 39, f. 1, la (1790).

Bartica; Mabaruma; Kaieteur Falls, etc. A very common species.

383. Nymphidium baeotia.

N. baeotia, Hewitson, Ex.- Butt. I, Nymphidium, t. 1, f. 5 (1862).
Demerara; Annai; Carimang River; Mabaruma; Parika; Kaieteur Falls.
Abundant in many places.

384. Nymphidium mantus.

Papilio mantus, Cramer, Pap. Ex. I, t. 47, F, G (1779).

Annai; Quonga; Carimang River.

385. Nymphidium caricae.

Papilio caricae, Linnaeus, Syst. Nat. I, p. 484, n. 158 (1758).
Generally common in all forest districts.

386. Nymphidium acherois.

Desmozona acherois, Boisduval, Spec. Gen. I, t. 21, f. 1 (1836).
Bartica; Annai; Carimang River; Takutu; Kaieteur Falls.

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AGRICULTURAL JOURNAL OF BRITISH GUIANA.

fX i.

387. Nymphidium cachrus.

Papilio cachrus, Fabricius, Mant. Ins. II, p. 78, n. 715 (1787).
Generally distributed and very common.

388. Nymphidium menalcus.

Papilio mevalcus, Cramer, Pap. Ex. IV, t. 290, K (1782).

Mabaruma; Kaieteur Falls. Perhaps only a form of N. cachrus, in which
case the name has priority.

389. Nymphidium calyce.

N. calyce, Felder, Wien. Ent. Mon VI, p. 72, n. 41 (1862).

Potaro River. Probably also elsewhere as it is a very common species in
most parts of its extensive range.

390. Baeotis hisbon.

Papilio hisbon, Cramer, Pap. Ex. I, t. 83, C (1779).

Demerara (G. Rodway).

391. Thisbe irenaea.

Papilio irenaea, Cramer, Pap. Ex. IV, t. 328, C, D (1782).

Annai; Quonga; Mt. Roraima. Unlike most, of this group, this species
always settles with the wings closed.

392. Anatole zygia.

Lemonias maculata zygia, Hubner, Samml. Ex. Schmett. (1806-16).
Quonga; Upper Corentyne.

393. Tharops hebrus.

Papilio hebrus, Cramer, Pap. Ex. I, t. 50, E, F (1779).

Potaro River.

394. Tharops menander.

Papilio menander, Cramer, Pap. Ex. IV, t. 334, C, D (1782).

Demerara River; Potaro River.

395. DYSMATHIA PORTIA.

D. portia. Bates, Journ. Linn. Soc. Zool. IX, p. 383 (1868).

In the British Museum from “ British Guiana.”

396. Pandemos pasiphae.

Papilio pasiphae, Cramer, Pap. Ex. I, t. 80, E (1779).

Demerara (Rodway) ; Annai; Carimang River; Potaro River. One of the
largest species of the family and always rare.

397. STALACHTIS EUTERPE.

Papilio euterpe, Linnaeus, Syst. Nat. I, p. 466, n. 49 (1758).

Annai; Kamakusa; Kuturi River.

$98. STALACHTIS CALLIOPE.

Papilio calliope, Linnaeus, Syst. Nat. I, p. 466, n. 46 (1758).

Annai; Kuturi River. Apparently common at Annai.

CATALOGUE OF THE LEPIDOPTBRA EHOPALOCERA OF BRITISH GUIANA. 159

899. STALACHTIS PHAEDUSA.

S. phaedusa, Hiibner, Zutr. Ex. Schmett. f. 13, 14 (1818).

Potaro Road; Kuturi River.

400. STALACHTIS DUVALII.

Heliconius duvalii, Perty, Del. Anim. Art. p. 153, t. 30, f. 1, lb
(1830-34).

In the British Museum from British Guiana.

401. STALACHTIS ZEPHYRITIS.

Papilio zephyr it is, Dalman, Anal. Ent. p. 47 (1823).

Bartica; Carimang River; Kamakusa.

402. Aricoris lagus.

Papilio lagus, Cramer, Pap. Ex. II, t. 117, F, G (1779).

Demerara; Bartica; Quonga; Carimang River; Mt. Roraima.

403. Aricoris salvini.

A. salvini, Staudinger, Ex. Tagf, I, p. 264, t. 93 (1888).

Mt. Roraima.

404. Theope EUDOCIA.

T. eudocia, Westwood, Gen. Diurn. Lep. p. 439, t. 70, f. 4 (1861).

Annai; Quonga; Carimang River. Some very interesting notes on the
association of the larvae of this species with ants are given by P. L. Guppy in
Kaye’s “ Catalogue of the Butterflies of Trinidad ”.

405. Theope hypoxantiia.

T. hyporantha, Bates, Journ. Linn. Soc. Zool. IX, p. 405 (1868).
Carimang River.

406. Theope foliorum.

T. foliorum, Bates, Journ. Linn. Soc. Zool, IX, p. 407 (1868),

Potaro River (Kaye).

407. Theope lycaenina.

T. lycaenina, Bates, Journ. Linn. Soc. Zool. IX, p. 406 (1868).

Annai; Carimang River.

408. Theope comosa.

T. comosa, Stichel, Gen. Ins. 112, p. 356.

Tumatumari (W. J. Kaye).

409. Theope sericea.

T. sericea, Bates Journ. Linn. Soc. Zool. IX, p. 404 (1868).

Annai; Carimang River.

410. Theope thestias.

T. thestias, Hewitson, Ex. Butt. II, Theope, t. 1, f. 5, 6 (1860).
Potaro River (C. B. Roberts).

160

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

rx, s.

Family LYCAENIDAE.

411. Hemiargus hanno.

Papilio hanno, Stoll, Suppl. Cram. Pap. Ex. t. 39, f. 2 (1790).
Generally distributed and common, frequenting dry grassy places neat
cultivation.

412. LEPTOTES CASSIUS.

Papilio Cassius, Cramer, Pap. Ex. I, t. 23, C, D (1776).

Carimang River; Mabaruma; Mt. Roraima. A common and probably
generally distributed species.

413. Theclopsis eryx.

Papilio eryx, Cramer, Pap. Ex. II, t. 143, D (1779).

Mabaruma (A. Hall).

Genus theola f.,

This extensive genus is here treated in its broadest sense as is done in
Seitz’s “American Rhopalocera ” ; the attempts of various authors to divide it
up into a number of genera have not met with general acceptance.

414. Thecla imperialis.

Papilio regalh, Cramer, Pap. Ex. I, t. 76, E, F (1779).

Mabaruma.

416. Thecla regalis.

Papilio regalis, Cramer, Pap. Ex. I, t. 72, E, F (1779).

I found a wing of this fine species in a spider’s web at the Kaieteur Falls

416. Thecla ganymedes.

Papilio ganimede8, Cramer, Pap. Ex. I, t. 40, C, D (1776).

Potaro River.

417. Thecla batesii.

T. batesii, Hewitson, 111. Diurn. Lep. p. 72, t. 27, f. 6. (1865).
Carimang River.

418. Thecla ornatrix.

T. ornatrix, Druce, Proc. Zool. Soc. 1907, p. 670, t. 31, f. 5.

Described from the Demerara River.

419. Thecla nobilis.

T. nobilis, Herrich-Schaeffer, Ex. Schmett. f. 66, 66 (1863).

^ Potaro River (W. J. Kaye, May 1901).

420. Thecla telemus.

Papilio telemus, Cramer, Pap. Ex. I, t. 4, D, E (1776).

Carimang River; Mt. Roraima. ,

CATALOGUE OF THE LEPIDOPTEEA RHOPALOCERA OF BRITISH GUIANA. 161

421. THECLA VENULIUS.

Papilio vemlius, Cramer, Pap. Ex. Ill, t. 243, G (1782).

Annai.

422. Thecla satyroides.

T. satyroides, Hewitson, III. Diurn. Lep. p. 74, t. 29, f. 10, 12, 13
. (1865).

Anna!.

423. Thecla marsyas.

Papilio marsyas, Linnaeus, Syst. Nat. I, p. 482, n. 149 (1758).
Generally distributed but never abundant. In the Botanical Gardens at
Georgetown (A. Hall). '

424. Thecla lisus.

Papilio lisus, Stoll, Suppl. Cram. t. 38, f. 2, 2b (1790).

Carimang River.

425. Thecla viresco.

T. viresco, Druce, Proc. Zool. Soc. 1907, p. 572.

Described from British Guiana.

426. Thecla hemon.

Papilio hemov, Cramer, Pap. Ex. I, t. 2, D, E (1775).

Bartica; Mabaruma; Carimang River. Fairly common.

427. Thecla mavors.

Theritas mavors, Hiibner, Zutr. Ex. Schmett. f. 189, 190 (1818).
Bartica; Carimang River; Mt. Roraima.

428. Thecla didymaon.

Papilio didymaon, Cramer, Pap. Ex. II, t. 134, A (1779).

Quonga; Carimang River; Mt. Roraima.

429. Thecla phaleros.

Papilio phaleros, Linnaeus, Syst. Nat. I, (2), p. 796 (1767).

Parika; Rockstone.

430. Thecla numen.

T. numen, Druce, Proc. Zool. Soc. 1907, p. 574, t. 32, f. 6.

Decribed from Mt. Roraima. A very distinct species.

431. Thecla linus.

Papilio linus, Sulzer, Gesch. Ins. t. 19, f. 10, 11 (1776).

Perhaps the commonest species of the genus. Abundant in all swampy
places. ( Larva on Solanum.

432. Thecla dolylas.

Papilio dolylas, Cramer, Pap. Ex. II, t. Ill, B, C (1779).

Quonga; Carimang River; Mabaruma. „

488. Thecla palegon.

Papilio palegon, Cramer, Pap. Ex. Ill, t. 282, C, D (1782).

Demerara $iver.

162

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

rx, a.

434. Thecla TEMESA.

T. temesa, Hewitson, Desc. Lye, p. 1, n. 2 (1868).

Anna!; Kaieteur Falls.

436. Thecla color.

T. color, Druce, Proc. Zool. Soc. 1907, p. 681, t. 33, f. 11.

Deecribed from British Guiana. Also in the British Museum from Annai.

436. Thecla sista.

T. sista, Hewitson. 111. Diurn. Lep. p. 91, t. 37, f. 98, 99 (1867).
Carimang River; Mt. Roraima.

437. Thecla ergina.

T. ergina, Hewitson, 111. Diurn. Lep. p. 105, t. 43, f. 170, 171 (1867).
Kaieteur Falls.

438. Thecla functum.

T. punctum, Herrich-Schaeffer, Ex. Schmett. f. 67, 68 (1863).

Annai, Chalk Hill, Essequibo (Coll. Ent. Div.).

(

439. Thecla munditia.

T. munditia, Druce, Proc. Zool. Soc. 1907, p. 686, t. 34, f. 10, 11.
Types from Bartica.

440. Thecla columbicola.

T. columbicola, Strand, Lep. Niep. (1), p. 16, t. 14, f. 27, 28 (1916).
Mabaruma (A. Hall).

441. Thecla ingae.

Papilio ingae, Sepp, Surin. Vlind. I, t. 17, (1848).

Quonga; Mabaruma.

442. Thecla cauter.

T. cauter, Druce, Proc. Zool. Soc. 1907, p. 689, t. 84, f. 15.

Described from “ British Guiana ”.

443. Thecla nivepunctata.

T. nivepunctata, Druce, Proc. Zool. Soc. 1907, p. 692, t. 36, f. 1.

Also described from 44 British Guiana ”.

444. Thecla syncellus.

Papilio syncellus, Cramer, Pap. Ex. IV. t. 334, A, B (1782).

Carimang River.

446. Thecla pelion.

Papilio pelion, Cramer, Pap. Ex. I, t, 6, E, F (1775).

Demerara River; Annai; Rockstone and Berbice.

446. Thecla strephon.

Papilio strephon, Fabricius, Syst. Ent. p. 622, n. 334 (1776).

Annai; Mt. Roraima.

. CATALOGUE OP THE LEPIDOPTERA RHOPALOCERA OP BRITISH GUIANA. 163

447. Thecla cyllarus.

Papilio cyllarus, Cramer, Pap. Ex. I, t. 27, C, D (1776).

Parika; Annai; Carimang River; Kaieteur Falls; Mabaruma.

448. Thecla syedra.

T. syedra, Hewitson, 111. Diurn. Lep. p. 108, t. 39, f. 128, 129; t. 41,
1 146 (1867).

Annai.

449. Thecla falerina.

T. falerina, Hewitson, 111. Diurn. Lep. p. 96, t. 43, f. 168, 169 (1867).
Annai.

460. Thecla pholeus.

Papilio pholeus, Cramer, Pap. Ex. II, t. 163, D, E (1779).

Carimang River; Oronoque-New River confluence.

451. Thecla echion.

Papilio echion, Linnaeus, Syst. Nat. I, (2), p. 788, n. 224 (1767>.

In the Botanical Gardens, Georgetown. Probably to be found elsewhere
in the vicinity of orange trees.

*152. Thecla crolus.

Papilio crolus, Cramer, Pap. Ex. IV, t. 333, G, H (1782).

Annai; Carimang River.

453. Thecla erema.

T. erema, Hewitson, 111. Diurn. Lep. p. 104, t. 44, f. 179, 180 (1867).
Annai.

454. Thecla picus.

T, picus, Druce, Proc. Zool. Soc. 1907, p. 606, t. 36, f. 9.

Described from British Guiana.

455. Thecla hesperitis.

Calycopis hesperitis, Butler & Druce, Cist. Ent. I, p. 107, (1872).
Annai; Mabaruma.

456. Thecla beon.

Papilio beon, Cramer, Pap. Ex. IV, t. 319, B, C (1782).

Generally distributed and common. One of the smallest and most abundant
species and rather variable.

457. Thecla atrius.

* T . atrius, Herrich-Schaeffer, Ex. Schmett. t. 14, f. 53, 54 (1853).
Annai; Quonga; Carimang River.

458. Thecla puppius.

T. puppius, Godman & Salvin, Biol. Cent.-Am. Rhop. II, ps 84 (1887).
Described from “British Guiana”. In the British Museum from Cari-
mang River, Annai and Mt Roraima.

tx, 8.

184 AGRICULTURAL JOURNAL OF BRITISH GUIANA.

459. THECLA CERATA.

T. cerata, Hewitson, III. Diurn. Lep. p. 191, t. 76, f. 607, 608 (1877).
Mabaruma.

460. Thecla caesaries.

T. caesaries, Druce, Proc. Zool. Soc. 1907, p. 614, t. 86, f. 19.
Described from Bartica.

461. Thecla celmus.

Papilio celmus, Cramer, Pap. Ex. I, t. 55, G, H. (1779).

Parika; Bartica; Annai; Carimang River; Mt. Roraima. A common
species. '

462. Thecla calchinia.

T. calchinia, Hewitson, Descr. Lyc. p. 21, n. 46 (1868).

Mt. Roraima.

463. Thecla doryasa."

T. doryasa, Hewitson, III. Diurn. Lep. p. 180, t. 70, f. 527, 628 (1874).
Demerara.

464. Thecla spurina.

*T. spurina, Hewitson, 111. Diurn. Lep. p. 102, t. 39, f. 122, 123 (1867).
In the British Museum from Berbice.

465. Thecla buphonia.

T. buphonia, Hewitson, Descr. Lyc. p. 25 (1868).

Carimang River.

466. Thecla torqueor.

T. torqueor, Druce, Proc. Zool. Soc. 1907, p. 608.

Carimang River.

467. Thecla xeneta.

T. xyneta, Hewitson, 111. Diurn. Lep. p. 193, t. 77, f. 611, 612 (1877).
Annai; Carimang River; Mt. Roraima.

468. Thecla foti.

T. foyi, Schaus, Proc. U.S. Nat. Mus. XXV, p. 417.

Omai.

469. Thecla athymbra.

T. athymbra, Hewitson, 111. Diurn, Lep. p. 92, t. 86, f. 91, 92 (1867).
Quonga; Takutu.

470. Thecla matho.

T. matho, Godman & Salvin, Biol. Cent.-Am. II, p. 80 (1887).

Types from the Carimang River.

471. Thecla simaethis.

Papilio simaethis, Drurg, 111. Ex. Ent. I, t. 1, f. 8 (1778).

Demerara River. A very widely distributed West Indian species but
always found singly.

CATALOGUE OF THE LEPlDOPTERA RHOPALOCERA OF BSIT^H GUIANA. 105
472. Thecla VOLUP1A.

T. volupia, Hewitson, 111. Diurn. Lep. p. 177, t. 69, f. 617, 618 (1874).
Mabaruma.

Family PIERIDAE.

478. PIERIS MONUSTE.

Papilio monuste, Linnaeus, Mus. Ulr. p. 237 (1764).

The “ Common White ” of South America. Generally distributed and
abundant, frequenting open or cultivated places.

474. PlERIS BUNIAE PHALOE.

P. phaloe, Godart, Enc. Meth. IX, p. 166 (1819).

Annai; Berbice (Coll. Ent. Div.).

475. ITABALLIA DEMOPHILE.

Papilio demophile, Linnaeus, Syst. Nat. I, (2), p. 761, n. 82 (1767).
Berbice.

476. PERRHYBRIS PYRRHA.

Papilio pyrrha, Fabricius, Syst. Ent. p. 464, n. 96 (1775).

Annai.

477. Archonias bellona.

Papilio bellona, Cramer, Pap. Ex. I, t. 13, E, F (1775).

There may be two races of this species in British Guiana. Specimen from
Annai in the British Museum are typical but those from Mt. Roraima have the
discal spots of the fore wings much shorter and the subapical spots absent. I
have not seen sufficient specimens to say whether the difference is constant.

478. Appias drusilla.

Papilio drusiUa, Cramer, Pap. Ex. II, t. 207, C (1779).

Generally distributed and periodically common.

479. Daptonoura lycimnia.

Papilio lycimnia, Cramer,' Pap. Ex. II, jt. 105, E, F (1779).

Potaro River; Carimang River; Mabaruma; Mt. Roraima.

480. HESPEROCHARIS nymphaea.

H. nymphaea, Moschler, Verh. z. b. Wien XXVI, p. 296, t. 3, f. 1 (1876).
Tumatumari; Potaro River. A rare species.

481. Leucidia brephos.

Mancipium vorax brephos, Hiibner, Samml. Ex. Schmett. (1806-16).

Bartica; Potaro Road; Mabaruma; Kaieteur Falls. This delicate little
species has a very weak flight.

482. TERIAO LEUCE. „

T. leuce, Boisduval, Spec. Gen. I, p. 659, n. Id (1936).

Mabaruma.

AottiClfttUfeAL JOURNAL of- lfciftek GtiiAJiA. tX 3.

488. Terias venusta limbia.

T. limbia, Felder, Wien Erit. Mon. V, p. 86, n. 47 (1861).

Generally distributed but less abundant than in some of the neighbouring
countries.

484. Terias albula.

Papilio albula, Cramer, Pap. Ex. I, t. 27, E (1776).

Common almost everywhere.

485. Terias agave.

Papilio agave, Cramer, Pap. Ex. I, t. 20, H, I (1775).

A very local species, I found a colony of it near the Penal Settlement on
the Mazaruni in February 1936. This is the only record I know of.

486. Terias elathea. *

Papilio elathea, Cramer, Pap. Ex. II, t. 99, C, D (1779).

Widely distributed but not very abundant.

487. Terias daira lydia. <

T. lydia, Felder, Wien Ent. Mon. V, p. 87, n. 50 (1861).

Quonga. Perhaps often overlooked owing to its close resemblance to
T. elathea,

488. Terias gratiosa.

T. gratiosa, Doubleday Hewitson, Gen. Diurn. Lep. t. 9, f. 5 (1847).

I have only seen two old specimens in a French collection labelled “ Guyane
Anglaise,” but as the species is common in Venezuela there is no reason to
doubt the record.

489. Catopsilia eubule.

Papilio eubule, Linnaeus, Syst. Nat. I, (2), p. 764, n. 102 (1767).

One of the commonest butterflies everywhere but apparently not addicted
to migrating or congregating in swarms like some of the other species of its
genus.

490. Catopsilia philea.

Papilio philea, Linnaeus, Syst. Nat. I, (2), p. 764, n. 104 (1767).
Widely distributed but not as a rule very abundant.

491. Catopsilia argante.

Papilio argante, Fabricius, Syst. Ent. p. 470, n. 116 (1776).

Generally distributed and often common.'

492. Catopsilia trite.

Papilio trite, Linnaeus, Syst. Nat, I, p, 489, n. 70 (1758).

Generally distributed but as a rule the least abundant of the species found
within our area.

CATALOGUE 6t THE lM>rW>PTE&A Rft6EAtOCfeRA OP BRITISH etiiAiU. 16?

493. Catopsilia statiba,

Papilio statira, Cramer, Pap. Ex. II, t. 120, C, D (1779).

Very abundant, especially at certain periods. Many records of the vast
migratory swarms of this species have been published by C. B. Williams and
others. Owing to its fondness for flying over water it is often to be seen in
large numbers by travellers on the rivers.

494. Gonepteryx menippe.

Mancipium fidelis menippe, Hiibner, Samml. Ex. Schmett. (1806-16).
Marudi Mtn., Rupununi District. (L. H. J. Ashburner).

496. DlSMORPHIA LICINIA.

Papilio licinia, Cramer, Pap. Ex. II, t. 163, E, F (1779).

Takutu; Mabaruma.

496. DlSMORPHIA CARTHESIS.

Leptalis car thesis, Hewitson, Trans. Ent. Soc. 1869, p. 71.

There are single males in the British Museum from Demerara (type) and
Quonga but it is a very rare species everywhere.

497. DlSMORPHIA AMPHIONE. ‘

Papilio amphione, Cramer, Pap. Ex. Ill, t. 232, E, F (1782).
Demerara River; Berbice; Takutu. Rare.

498. DlSMORPHIA CRISIA RORAIMAE.

D. crisia roraimae, subsp. nov.

Description. Male. All white markings reduced as compared with the
darkest specimens of D. crisia foedora Lucas, faintly yellowish; the two parts
of the band of fore wings well separated; in the anterior section the middle
discocellular is broadly black so that the white spot in the cell is partly separ-
ated from the rest of the band.

Female. The light markings always yellowish, the spot in the cell of fore
wings partly separated from the rest of the band as in the male.

Described from six males and four females from Mt. Roraima in the
British Museum.

499. DlSMORPHIA PROSERPINA.

D. proeerpina, Grose Smith & Kirby, Rhop. Ex. II, p. 11, Dismorphia,
t. 3, f. 1, 2, 8 (1897).

Described from Mt. Roraima and only known from there.

600. DlSMORPHIA TAPAJONA.

Leptalis tapajona, Bates, Joui;\. Ent. I, p. 231, n. 3 (1861).

Oarimang River; Cuyuni. I think this may prove to be the female of
D. laia, Cramer, males of which are known from Surinam and French Guiana.

601. DlSMORPHIA PINTHAEUS.

Papilio pinthaeus, Linnaeus, Mu3. Ulr. p. 268 (1764)..

Bartica; Carimang River; Kaieteur Falls; Mt. Roraima. Only found
singly, generally in company with the species of Aeria and Scada which serve
as its models.

168' AGRICULTURAL JOURNAL OP BRITISH GUIANA. tX, 3.

Family PAPILIONIDAE.

502. PAPILIO TRIOPAS MITHRAS.

P. mithras, Grose Smith, Rhop. Ex. Ill, Papilio t. 23 f. 1 (1902).
Demerara River; Bartica; Annai; Carimang River. Always a rare specifes.

503. Papilio aeneas.

P. aeneas, Linnaeus, Syst. Nat. I, p. 461, n. 15 (1758).

Demerara River; Bartica. Rather scarce. Camaria.

504. Papilio sesostris.

P. sesostris, Cramer, Pap. Ex. Ill, t. 211, F, G (1779).’

Parika; Bartica; Annai; Quonga; Kaieteur Falls. This beautiful species
is not rare in heavy forest.

605. Papilio phosphorus.

P. phosphorus, Bates, Trans. Ent. Soc. 1866, p. 342, note.

The type male came from Demerara and there are specimens in the Tring
Museum from British Guiana but it is evidently a rare species.

506. Papilio vertumnus.

Pi vertumnus, Cramer, Pap. Ex. Ill, t. 211, A, B (1782).

Demerara; Essequibo River; Camaria; Kaieteur Falls. A scarce and local
species.

507. Papilio anciiises.

P. anchises, Linnaeus, Syst. Nat. 460, n. 10 (1758).

Specimens from Quonga and “ British Guiana ” in the British Museum
(two males) are intermediate between the typical form and the race osyrin
Felder from Venezuela.

508. Papilio panthonus.

P. panthonus, Cramer, Pap. Ex. Ill, t. 278, C, D (1782).

Demerara River; New Amsterdam; Bartica; Parika. Not very common
where it is found.

509. Papilio lysander.

P. lysander, Cramer, Pap. Ex. I, t. 29, C, D (1775).

Bartica; Akyma; New Amsterdam; Berbice River; Mabaruma; Kaieteur
Falls. One of the commoner species.

510. Papilio eciiemon ergkteles.

P. ergeteles, Gray, Cat. Lep. Ins. Brit. Mus. p. 62, t. 8, f. 5 (1852).
Annai; Camaria; Demerara River.

611. Papilio neophilus.

Priamides neopihlus, Hiibner, Zutr. Ex. Schmett. F. 997, 998 (1837)
Bartica; Annai; Quonga. Not very common.

CATALOGUE OF THE LEPIDOPTERA BHOPALOCERA OF BRITISH GUIANA. 169

612. PAPILIO ABCAS.

P. areas, Cramer, Pap. Ex. IV, t. 378, C (1782).

Recorded by Kaye from British Guiana. I have not seen a specimen but
as it is a fairly common species in Venezuela on the one hand and Surinam on
the other its existence in our Colony may be safely accepted.

613. Papilio polydamas.

P. polydamas, Linnaeus, Syst. Nat. I, p. 460, n. 11 (1858).

Generally distributed but less abundant than in most parts of South
America.

614. Papilio belus.

P. belus, Cramer, Pap. Ex. IT, t. 112, A, B (1779).

P. caburi, Kaye, “Entomologist” XXXIX, p. 51, t. 2, f. 1 (1906).

A female taken by W. J. Kaye on the old Caburi Road and forming the
type of his P. caburi is the only British Guiana specimen I know of.

515. Papilio crassus.

F. crassus, Cramer, Pap. Ex. II, t. 112, C (1779).

In the British Museum from Berbice and in the Tring Museum from
British Guiana.

616. Papilio thoas.

P. thoas, Linnaeus, Mant. Plant, p. 536 (1771).

Generally distributed and moderately common.

517. Papilio androgeus.

P. androgens, Cramer, Pap. Ex. I, t. 16, C, D (1775).

Berbice; Bartica; Essequibo River. The female of this species is trimor-
phic but all the females I have seen from British Guiana are of the form
piranthns Cramer ("Pap. Ex. Ill, t. 204, A, B (1782).

518. Papilio hyppason.

P. hyppason, Cramer, Pap. Ex. I, t. 29, E (1775).

Demerara River; Berbice. A rare species."

519. Papilio anchisiades.

P. anchisiades, Esper, Ausl. Schmett. t. 13, f. 1, 2 (1788).
Georgetown; Berbice; Omai; Mabaruma. Sometimes a fairly common
species. The larva feeds upon Citrus and is easy to rear.

520. Papilio torquatus.

, P. torquatus, Cramer, Pap. Ex. II, t. 177, A, B (1779).

In the Georgetown Museum without locality and in the British Museum
from “British Guiana.”

METEOROLOGICAL DATA— APRIL $0 JUNE, IMS.

Rain-

fall.

NUlfBE* 0? PATS OT RAIN

Evapo-

ration

JUr ?•« jMVfttu**
ud Humidity.

Botanic Gardens.

1 1
H-4

S 1

s -s

S >S&
2 8

InohM

April

4.78

83.7

79.8

81.0

May

7.25

...

5.09

84.5

76.4

80.4

80.8

Jane

7.53

...

4.33

84.8

76.1

80.4

83.8

Totals

23.58

14.20

...

Means

1 -

...

84.3

76.2

80.2

81.9

Berbice Gardens.

April

IS . 21

83.7

73.5

78.6

85.8

May

5.02

• M

...

86.1

72.4

79.2

80.1

Jane

11.10

...

86.2

74.9

80.5

82.6

Totals |

34.33

35 j

! 5

(59

...

Means

...

i - !

1 ...

...

85.3

73 .C

79 4

82.8

Onderneeming.

April

5.60

...

••

May

5.24

...

June

10.16

;

...

Totals j

21.00

| 11

...

Means

...

—

...

-1

...

Hosororo,

North West District

•

April

6.65

...

S 3

...

86.0

71.2

78.6

83.4

^May

6.91

...

88.6

71.2

79.9

81.8

Jane

12.52

...

85.2

71.8

78.5

88.4

- Total*

26.08

••i

•••

•««

...

Mean*

...

• M

...

86.6

71.4

84.5

Records inaccurate,

Vol. X, Mo. 4.

December, 1939

The

Agricultural Journal

British Guiana

PUBLISHED BY

THE DEPARTMENT OF AGRICULTURE

GEORGETOWN, BRITISH GUIANA

Price

6d.

DEPARTMENT OF AGRICULTURE.

ADMINISTRATION

Director of Agriculture ...

...

Deputy Director

Clerical

Chief Clerk

Registrar of Banks

Accountant

Record Clerk

...

Typist Clerks

...

Probationers

...

Librarian

...

RESEARCH BRANCH.

Botany and Plant Pathology

Botanist — Plant Pathologist and Superintend-
ent , Botanic Gardens :

E. B. Martyn, B.A., A.U.T.A.

Technical Assistant : N. Persaud

Chemistry

Chemist :

D. W. Duthie, M.A.. B.Sc.. Ph.D.. F.I.C.

Assistant Chemist *

C. L. C. Bourne

Economics

Agricultural Economist :

H. D. Huggins, M,Ht\.Dip. Apr.

Entomology

Entomologist :

L. 1), Cleare, F.R. Knt. ft.

Technical Assistant : C. Williams

Rice

Assistant Plant Breeder :

P. A. ChanChoong, B.Sc., A.IC.T A.

Sugar

(In co-operation with the Sugar Producers)
Sugar Agronomist and Plant Breeder :

C. H. B. Williams, M.A., A.I.C.T.A.. Dip. Agr.

Laboratory Assistants : H. B. Singh

A, T. Wan-Ping, Dip. Agr.
Statistical Assistant : J. B. Bourne, F.ae.

LIVESTOCK BRANCH

Veterinary Surgeon :

H. A Fraser, Sc,

... Prof. The Hon. J. Sydney Dash,

B.Sc. (Agric.)

(vacant)

L. D. Cleare, F.B. Ent. S. (acting)

Staff.

... J. F. Irving, M.c.

W. G. Delph
A. A. Thorne

... Miss D. M. Terrill

{ Miss M, Cheong
Miss S. Lord
Miss M. R. Christian!

P. 0. Jackson
S. A. Adams
M. R. Chase
Miss V. Chan-Choong

FIELD BRANCH

Agricultural Superintendents :

Berbice— A. A. Abraham
Demerara, East — M. A. G. Hanschell,

B.A., Dip. Agr.

Demerara, East Bank — H. D Huggins,
Dip. Agr.

Demerara, West— E. G. Benson, B.sc.,
a.i.c.t.a., Dip. Agr. (on leave)
Essequibo— T. Bell, n.s.A., a.i.c.t.a.

Assistant Agricultural Superintendent :

West Demerara— E. M. Morgan

Agricultural Instructors :

Berbice— O. F. J. Cliuraman, Dip. Agr.
Botanic Gardens— H. A. Cole (on leave)
Demerara, East— C. C. Dowding, f.l s,
f.h.h.s.

Agricultural Assistants:

Deniferara, East — J. Indrobeharry
Essequibo— H. B. France

Technical Assistants :

Demerara, East — W. A. Bo veil

Essequibo— A. W. Sears

North West District — L. E. McKinnon

Sugar

Field Manager (Central Station)

C. Cameron
Field Assistants '

L. A. Forte

B. A. McArthur m

TOBACCO

Tobacco Officer :

T. W, Bradshaw% m.c.

METEOROLOGICAL BRANCH

Technical Assistant ;

D. D> Blackman

Meteorological Assistant :

J. E. Isaacs

RICE GRADING BRANCH

Grading Inspector :

H. E. H. Gadd

Technical Assistants :

R. R. Ross
G. L. Leitch

ADVISORY BOARD OF AGRICULTURE

Director of Agriculture, Chairman, ex officio .

Deputy Director of Agriculture, Vice-Chairman, ex officio.

Hon. Peer Bacchus
Hon. R. E. Brassington
Hon. J. W. Jackson
Hon. F. J. Seaford, o.b.e
Mr. S. Andries
., R. B. Hunter
W. H. Richards

)

Members

SUGAR EXPERIMENT STATIONS’ COMMITTEE.

Director of Agriculture, Chairman, ex-officio.
Hon. M. B G. Austin, o.b.e.

Mr. J. Bee

„ G. M, Ecclos
„ J. C. Gibson

„ G. Gleadow
„ G. H. Holden

Oeprgetown ^

Messrs. Curtis ('amp- I

bell & Co., Ltd.

Pin. Blairmont >

Messrs. Booker Bros. |

McConnell & Co. Ltd.
Pin. Uitvlugt I

Pin. Diamond '

Represent]
the Suss
Industr
which mal
tains tt
Stations

CO-OPERATIYE CREDIT BANKS’ BOARD.

Director of Agriculture, Chairman, ex-officio.
Dr. the Hon. J. B. Singh
Rev. A. E. Dyett ...

Mr. C. Farnum ...

J.L. Wills ...

Members

CONTENTS

(Vol. X, No. 4.)

Page

EDITORIAL- 171

SUSPENSION OF PUBLICATION— ... 172

ORIGINAL ARTICLES.

The Soils of British Guiana
South of the 5th Parallel,
and of the North-West

District . . J). W. Duthe, Ph.D., F.I.C. ... 173

Mineral Deficiency and
Cattle Raising in British

Guiana ... D. W. Duthie, Ph.D., F.I.C. ... 194

Irrigation-Manorial Trials
with Sugar-cane on Flood -

Fallowed Frontland ... C. H. H. Wiliams, M.A., A.I.C.T.A.,

Dtp. Ayr. ... ... 205

Recent Introductions of Orna-
mental Plants in the
Botanic Garden, George-
town ... E. B. Martyn, BA., A.I.C.T.A. ... 210

Catalogue of the Lcpidopto a
rhopalocera (Butterflies) of

British Guiana (Coml udid) ... Arthur Hull, F.R., Ent .S'. ... 215

NOTE.

Minutes of the Seventeenth
Meeting of the Advisory

Board of Agriculture ... ... ... ... 253

PLANT AND SEED EXCHANGE ... ... ... * ... 257

METEOROLOGICAL DATA ... ... ... ... 260

The

Agricultural Journal of British Guiana

December, 1939,

EDITORIAL.

FOOD PRODUCTION CAMPAIGN.

The previous number of this Journal appeared soon after war was
declared. In that issue the desirability of growing more food was indicated
in a general way; the situation was new and planB were not sufficiently
advanced at that time to permit more specific treatment of the problem. The
situation is still new but sufficient has now been done to indicate the lines
along which the Colony is organizing itself to replace with its own products
food supplies previously obtained from abroad.

A Food Production Committee with the Director of Agriculture as
Chairman has been appointed to advise Government on the methods to be
adopted in this campaign. Wheat flour is, in value, the most important
single article of diet imported, and in view of the fact that supplies may
become expensive and irregular, investigations were begun at once in
connection with the substitution of some of the wheat flour used in bread
by rice flour. The bakers interviewed did not at first react favourably vo
the idea; they had had previous experience only with rice flour which was
not finely ground and which was unable to pass through anything finer
than a 40-80 mesh screen; their objection was found to be due mainly
to this fact. A first essential was therefore to produce in sample quan-
tities rice flour approximating wheat flour in fineness. This the Department
did. Several commercial bakeries helpfully co-operated in carrying out tri als
with bread containing 1 part of rice flour to 3 parts of wheat flour. Sam pia
loaves thus obtained were distributed to 200 households and the comments
received were, without exception, encburaging. At the stage now reached,
investigations are being made locally and abroad ir regard to suitable mill-
ing equipment and the cost of production in relation to wheat flour.

As local and Caribbean demands for rice are likely to become bigger,
growers are being encouraged to increase plantings. In conjunction with
this policy drainage and other agricultural conditions on the Government
estates in Essequibo are to be improved for extended rice and ground pro-
vision cultivations by tenant growers. There are already signs that the
coming spring crop will be much larger throughout the Colony than it was
this year, while the estimated production of the 1939 autumifl crop is the
highest since 1985. It is hoped that weather conditions, which always play
an important part, will be favourable.

172

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 4.

Id order to ensure orderly marketing and a satisfactory working arrange-
ment for supplying the neighbouring West Indian Colonies, Government has
instituted a comprehensive marketing scheme by which all the rice produced
for sale will be controlled by a central organization.

Peas, beans and lentils form another group of commodities which enter
largely into local consumption. Experience indicates that, among the pea
and bean group, the black eye pea is the one likely to be most rapidly extended
locally. District work has been undertaken to encourage the planting of
a sufficient area in the coming rains to render the Colony independent of
black eye pea imports, it being planned to grow two crops per year. Gov-
ernment is working out the details of a marketing scheme, the chief object
of which is to ensure orderly release of peas on the market; only if alter-
nating glut and scarcity are avoided can both grower and consumer reap
the full benefit of a rapidly expanding local black eye pea industry; in this
connection Government has provided a revolving fund of $8,000 for purchase
and storage expenses connected with the scheme.

A feature of the “ Grow More Food ” activities is the work being done
in the districts to help conserve planting material. Such material as it is
thought that farmers will find it difficult to procure is being obtained by the
Department. To ensure that planted areas will get a good start, not only
seeds, but in deserving cases seedlings, will be distributed. Supervision of
planting areas is being arranged for as far as practicable.

The production of more pickled meats is also being planned, the neces-
sity for supporting the section of the Colony’s population engaged in the
gold and other industries in the interior being borne in mind. Certain West
Indian markets, notably Trinidad, are likely to expect increased meat supplies
from this country.

Allotment areas are being established near to Georgetown and New
Amsterdam with the object of helping city dwellers to grow, at any rate in
part, some of their food requirements.

In the efforts connected with the “ Grow More Food ” campaign active
co-operation has been sought from, and assured by, the sugar estates. Advice
to farmers has been published in simple language in the Farm Journal,
reprints and leaflets distributed free of cost, and notes published periodically
in the Press. Wherever desirable extension work is being done in consultation
with the District Administration Staff and Village Authorities.

SUSPENSION OF PUBLICATION.

It has been decided that, as an economy measure, publication of the
Agricultural Journal of British Guiana will be suspended for the duration
of the war. This issue, which completes Volume X, will therefore be the
last until the cessation of hostilities. The index for the Volume has been
completed and is being distributed with this number.

ORIGINAL ARTICLES

THE SOILS OF BRITISH GUIANA SOUTH OF THE 5TH
PARALLEL, AND OF THE NORTH-WEST DISTRICT.*

D. W. DUTIIIE, ph.d,, F.i.c.

Chemist , Department of Agriculture .

CONTENTS.

1. General.

2 The Parent Rocks and Their Soil*.

X The Rain Forest Area of the Essequibo Basin.

4. The Rupununi Savannah Country,

The Chemical Composition of Savannah Pastures,

5. The Hilly Forest Country Bordering the Sa\ annahh.

Pakaraima Mountains,

The Kanaku Mountains.

M.irutli Mountain.

6 The Berbicr River and the Cattle Trail.

The Berbice River.

The Cattle Trail.

7. The Nortii-Wevt Dimtcict.

Acknowledgments.

APPENDIX.

Note* on Analytical Methods.

Table I. —Soils of the E^equibo By&in.

Table II, --Soils or the Rcpununi Savannahs.

Table III. -Soils of the Hilly Forest Country Bordering toe Savannah*.
Table IV. —Soils or the Berbice River Area.

l. General.

The physical texture of the soil was considered to be the most important
factor from the point of view of agricultural development by scientific methods,
and all samples were subjected to mechanical analysis by Robinson's method.
As the analytical data would be somewhat unwieldly in the main text, the
tablea qf results have been placed in an Appendix, with a note on the analytical
methods employed. Notes on the savannah pastures have also been included,
and the available analyses have been collected in *a table.

♦A report on the area examined by the British Guiana Smvey Commission function-
ing under the auspices of the President’s Advisory committee on Political Refugees.
Punished by permission of the Secretary of State for the Colonies and of the
Secretary of the President's Advisory Committee on Political Refugees, New York.

174

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

IX 4 .

The area has been divided into five sections :

(1) The rain forest area in the basin of the Essequibo River and its
tributaries.

(2) The Rupununi Savannah country.

(3) The hilly forest country bordering the savannahs.

(4) The Berbice River and the Cattle Trail.

(5) The North-West District

2. The Parent Rocks and Their Soils.

The age of the basement formation of British Guiana has not been
definitely determined, but it is believed to be mainly Archaean. It consists of
gneiss and metamorphosed sedimentary and volcanic rocks, intruded by granite
and younger dykes of dolerite and other basic rocks. It is presumed that the
Kaieteurean Sedimentary Series, which consists of sandstones, conglomerates,
quartzites and shales, was laid down on this basement, possibly over most of
the Colony. The age of this formation is not known; it has been compared
with pre-Cambrian, Devonian, Permian, Triassic ' and Cretaceous formations
of adjacent*countries, without definite conclusions being possible. Extensive
sills and dykes of gabbro and dolerite were subsequently intruded into the
Kaieteurean, block-faulting it into its present form. Subsequent erosion has
removed the Kaieteurean from most of the area, and it is now restricted to
the outlying mass forming the Pakaraima Mountains.

Wide stretches of alluvial deposits — Pleistocene or Recent — now occupy
the lower lands and river valleys. These were possibly derived from granites
and other members of the basement formation, and they consist of water-
worn sands of rather fine texture, interspersed with clays.

The basement locks, gneiss and granite, outcrop frequently along the
rivers, and from this it appears that they cover a large area of the country.
The soil derived from them varies from a pinkish-red silty loam in the
forest to a light yellow sand on the savannahs, the forest soils possessing
some natural fertility while the leached savannah soil is definitely infertile.
The basic intrusions produce a chocolate-coloured soil which has a high clay
content, and has all the chemical and physical indications of a naturally fer-
tile soil which would withstand continuous cultivation even under tropical
conditions.

The Kaieteurean Series gives rise to sandy soils of low fertility, but the
intrusive sills and dykes have formed restricted areas of more fertile soil, of
which several were found by Follett-Smith on his tour in 1985 with the'
League of Nations Commission for settling Assyrians. The area south of
6°N occupied by elevated land of this formation is relatively small, and is con-
9ned to a corner of the. Pakaraimas and a few isolated escarpment mountains.

The low-lying lands along the river banks do not give much promise of
agricultural development. The widely meandering rivers have occupied many
channels, and the light sandy alluvial deposits have been heavily leached by

THE SOILS OF BRITISH GUIANA.

175

periodic floodings. Areas of clay or loam would be much more amenable to
agricultural improvement, but it is uncertain to what extent these occur.
There iB usually a distinct "river terrace" several miles from the present
course of the river, and it is possible that there is an improvement in the
soil at that point

3. The Rain Forest Area of the Essequibo Basin.

Of approximately 40,000 square miles included in that part of British
Guiana which lies south of 5°N., some 35,000 square miles are under forest,
the basin of the Essequibo and its tributaries comprising the greater part of
this. No soil investigations have previously been carried out in that area, and
the scattered observations which were possible in the present survey are in-
sufficient to permit confident generalisation. Only by using geology as a basis
was jit possible to gain any broad idea of the potential agricultural value of
the area, but the geological information is also meagre, since detailed surveys
have not been carried out.

With these limitations in mind, we can visualise this area as consisting
partly of alluvial deposits and partly of granite with its basic intrusions.
That the area is fundamentally granite is indicated by the very frequent out-
crops of granite along all the river courses, but it is probable that the recent
alluvial sands and clays have covered the basement rocks over large areas,
particularly in river valleys.

The sandy alluvial soils are manifestly infertile, and this was amply de-
monstrated on an Indian farm at Rupununi Mouth, where even on newly
cleared land only cassava was thriving. This soil type was sampled in profile
in a grazing paddock at Apoteri and the analytical figures (Table I of Appen-
dix, E484-489) show it to be an acid sand with nearly 80% coarse sand, low
organic matter and nitrogen, and no available phosphate. The high clay con-
tent (37%) of the 30-36" sample suggests that most of the finer material had
been washed into the subsoil, but it is doubtful if any cultural method could
prevent this with the high rainfall of the district (86 ins. per annum at
Kurupukari). The clays which geologists have included in this alluvial
formation were not found, but they probably occur on some of the flat lands
near the rivers, or as hill-wash.

Some of the sandhills are capped with concretionary ironstone, which seems
to occupy only small areas. One of these hills, at Apoteri, was examined in
some detail, and it was found that, on the hilltop the ironstone was over
3 feet thick, while halfway down the hill it gave way to sand about 6 inches
from tike surface. As a soil it appears to be agriculturally useless.

Thus the sandy areas along the rivers appear to be unsuitable for agricul-
tural development, but there is the point that the accessible parts are old
river beds, and the soil may be different on the "river-terraces,” which, at
Apoteri, are about 8 miles from the present river bed.

Red soil overlying the granite formation was sampled in profile at
Massara, about 7 miles up the Essequibo River from Rupununi Mouth. It was

176

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 4.

rather shallow and gravelly, but apart from this it gave indications of being
a fertile soil. The coarse sand and clay fractions are approximately equal
('30% each) and the analytical figures (Table I of Appendix, E479-483)
show that it is only slightly acid; the organic matter and nitrogen are both
high, and the figure for available phosphate is high for a tropical forest soil'
This is the site of a Carib settlement which was abandoned over 30 years
ago, and the gravelly nature of the soil may be partly due to erosion, al-
though the ground is now covered with thick forest.

Approximately 2 miles downstream from Massara is an outcrop of a fine
grained epidiorite which has intruded into the granite. The soil overlying
this was also sampled, and proved to be heavier than that at Massara (44%
clay as compared with 30%); it also shows up on analysis (Table I, E477
and 478) as a fertile soil.

It is possible that there may be some association between the soil over-
lying granite at Massara and the basic dyke which was found two miles down-
stream. For instance, the Massara sample may have been derived from the
edge of the intrusion, and it is significant that the old geological maps of the
Colony mark a basic dyke at Massara. This i«f an important point, as it is
unlikely, in theory at least, that the gneissose granites of the basement
formation, could produce a fertile soil of good physical texture. In further
work it is essential to determine the difference between soils derived from
granite and those produced by weathering of the basic intrusive rocks.

A second deposit of moderately fertile red soil was found at an aban-
doned Boundary Commission camp at Oronoque Falls on the New River. The
analytical data for a series of samples of this soil are given in Table I
fE549-552). A similar type of soil was found in the Kanaku Mountains, on
Marudi Mountain, and by Follett-Smith in the Yawong Valley in the Paka-
raima Mountains, and these deposits are discussed in other sections of this
report.

In his visit to the Rupununi valley in the Kanaku Mountains, Sir Geoffrey
Evans found the fertile red soil to be associated with a palm, Orbignya
sagotii, which might be a useful indicator plant. It was seen from the air

during a reconnaissance flight up the Essequibo River (near Sawkins Island),

and a landing was made in order to identify the palm and to sample its soil.

The 0-6" and 6-12" samples did not conform to the idea that this palm is

an indicator of fertile red soil, but an ants’ nest nearby showed a bright red
soil which had been brought up from over two feet below surface. The
analysis of the top soil is given in Table I (E547 and 548) but samples of
the red subsoil could not be obtained at the time, and the ants’ nest material
would not be a suitable sample.

4. The Rupununi Savannah Country.

Investigations on the soils of the Rupununi savannahs have been carried
out by Sir John Harrison and by Mr. R. R. Follett-Smith. Harrison had no
opportunity of visiting these savannahs, but he reported on the examination
of five soil samples from the Rupununi District (Combined Court paper

THE SOILS OP BRITISH GUIANA.

177

No. 744, 1914). These samples were collected by Mr. H. P. C. Melville, then
Commissioner of the Rupununi District, and were taken from localities with-
in a radius of three miles from Dadanawa. As the comparable analytical
figures given by Harrison agree in the main with those of Samples collected
during the present survey, it will be sufficient to quote Harrison's conclusions :

“ The samples sent by the Commissioner, if, as he states they are,
“truly representative of the districts, indicate that by far the greatest
“ portion of the area is a coarse sandy soil of low fertility, apparently at
“present suited only to the production of coarse grasses for pastoral or
“ ranching purposes. Its very unfavourable physical condition does not
“ hold out any hopes of its ready amelioration by ordinary local cultural
“ methods. Where it is traversed by rivers and streams and their banks
“ are subject to flooding the soils are fertile and produce a “lush” grass
“ after such flooding. In places there are hollows or shallow depressions
“ in the savannahs where the soils are of considerable to high fertility,
“capable of producing many varieties of tropical products; whilst the
“ savannahs are traversed by ridges or so-called “islands” of land the
“ soil of which from its physical nature is of well-marked fertility.

“ In connection with the sandy savannahs it must be remembered
“ that modern agricultural science has changed and greatly improved
“ certain methods of cultivation and introduced new methods, with the
“ result that “today is the day of the sandy soils.” We therefore may
“ look forward to a time when the savannah soils of Berbice and of the
“ Rupununi may produce crops of kinds that at present I am unable to
“ indicate.”

One statement in the main part of Harrison’s report requiries comment.
In reporting on a sample “taken from one of the low wave-like ridges that

give these savannahs their rolling appearance This sample is

representative of about two-thirds of the savannah soil” he says :

“ As regards intensive cultivation the soil can only be classed in its
“present state as sterile to barren. I know of no tropical product other
“perhaps than Caera rubber that could be successfully raised on such
“a soil in its natural condition.

“ The agricultural improvement of this soil would not be difficult.
“ It would require deep ploughing so as to bring up the finer particles
“ of the subsoil or even the earth underlying the subsoil so as to mix
“with the somewhat coarse-textured surface-soil the finer-grained silt
“and clay derived from the lower layers. Phosphoric acid should be
“applied, preferably in the form of slag phosphates, in quantity from 6
“to 10 cwts. per acre ”

His analytical figures do not bear out this suggestion in regard to im-
proving the texture by deep ploughing, since- his coarse sand (2-0.2 mm)
figures for soil and subsoil (sampling depths are not recorded) are 73% and
67%, while the fine sand plus coarse silt (probabl> about 0.2*0.02 mm) per-
centages are respectively 27 and 25, clay being 4% and 7%. Large scale

176 ACBHCULTljBAL JOUENAL OP BWWISH GUIANA. tX 4*

cultivation of this soil would probably introduce serious erosion problems,
owing to the high winds which prevail during the greater part of the year
and the heavy rains during the wet season. On the other hand the cultiva-
tion of food crops by intensive methods is successfully practised by ranchers,
who obtain good yields in corrals which have been heavily manured by cattle,
horses, or sheep.

In their report on agricultural conditions in the Rupununi District ( Agr .
Jl. British Guiana, 1935, p. 155), Follett-Smith and Frampton give the
analytical data for an example of the topsoil occurring on the elevated land
of the northern savannahs. It is described as a markedly acidic light sand
containing only small amounts of organic matter and exchangeable bases.
The amount of readily available phosphate is low, and the value for the rate
of solution suggests that the soil is not particularly fertile. A sample taken
from a “bush island” in the southern savannah was also examined, and in
this case the values for exchangeable bases and for the rate of solution
suggested that this soil is more fertile than that of the open savannahs.

In order to test Harrison’s view that the sandy savannah soils could be
improved by deep ploughing, a profile pit was sampled in detail at Manari,
in the northern savannah. The analytical results in Table II of the Appendix
(E490-499) show that there is only a gradual change in texture with depth,
and that there is no definite layer of fine earth underlying the subsoil.
Ploughing to 2 feet would improve the texture slightly, cut Harrison’s words
should not be taken too literally, even although the Manari soil is heavier in
texture than the samples from Dadanawa which Harrison analysed. It is
only at a depth of 3 ft. that the clay percentage exceeds that of coarse sand,
and thus this soil will always be too light for extensive cultivation unless the
severest anti-erosion methods are adopted. A feature of this profile was
that the 3-12 inch horizon was dark in colour, baked, and compact, pre-
sumably on account of trampling by animals and of repeated savannah fires.
Light ploughing or harrowing would undoubtedly increase the growth of
grass, and might also improve the water relations of the soil, but its deficiency
in plant foods would have to be corrected by liberal manuring before vegetable
crops could be grown.

Two samples of top and subsoil were taken near Annai by Dr. Donovan
and Colonel Nicholas on their journey down the cattle trail, and the analytical
figures for these are also included in Table II (E516-519). One, taken at
mile 179i, represents the general soil type of the district and is somewhat
similar in texture to the Manari savannah soil; but the organic matter and
nitrogen are higher, possibly because there is more standing water in this dis-
trict during the wet season and therefore more opportunity for the accumu-
lation of plant debris. The second sample, taken from flat land near the Gov-
ernment Rest House, is heavier in texture, and resembles a soil which was
sampled near the creek at Manari and is discussed below.

One of Melville’s samples was " a dark soil of considerable fertility, taken
“ from flat land extending about 100 yards on cither side of a small creek

THE MILS OF BRITISH GUIANA.

170

" draining the savannahs. This is covered with water during the rainy sea-
“ son.” In his report Harrison says—

“Both the mechanical and chemical analyses of the soil fully bear
“out the Commissioner's opinion. The topsoil and subsoil are of very
“favourable mechanical composition, the soil being a fairly light loam.
“ In the soil itself two of the important constituents of plant food, nitro-
"gen and lime (calcium oxide), are present in satisfactory proportion,
“whilst potash and phosphoric anhydride are somewhat low even for a
“tropical residual soil. But the proportions of the mineral constituents
“ present in the subsoil indicate that with fairly deep cultivation the fer-
tility of the land would tend to increase. The soil has the character-
“istics of a tropical fertile river or valley alluvial soil. If planted as
“soon as possible after the termination of the rainy season this soil
“should give heavy crops of maize, Guinea corn, hill rice, tobacco and
“tropical garden crops generally.”

While there are no extensive areas of this soil type, there are many
small areas which agree with Melville's description, and it is interesting that
Sir Crawford Douglas-Jones was struck by their resemblance to the “vlei”
lands of Southern Rhodesia, which are cultivated in the manner suggested
by Harrison. Two such areas were sampled, one in the southern savannah
between Wariwau and Aishelton and one at Manari within a few yards of
the sandy profile pit, and the analytical figures i Table II, E531, 532. 534-546'
agree in general with Harrison's findings. In stock-farming these areas
would be of inestimable value for fodder grasses as well as food crops, since
Para Grass would undoubtedly flourish under these conditions.

The Chemical Composition of Savannah Pastures.

Samples of grasses from various parts of the Colony have been analysed
in the Chemical Division and reported on by Follett-Smith. Except for
those on the Government Stock Farm, Georgetown, where mineral mixtures
are regularly fed to the stock, all the pastures show an extreme deficiency of
phosphate, often accompanied by deficiencies in lime and potash. The figures
have been collected in the accompanying table and are compared with those
for a good natural British hill pasture, a poor Falkland Islands pasture, and
a pasture from Molo, Kenya, where striking results were obtained by feeding
mineral mixtures to the animals (Economic Advisory Council, 6th Report
of Committee on the Mineral Content of Natural Pastures, 1931). From a
search of the literature it appears that the limiting percentages of phos-
phorus in natural grazing is about 0.4, but it should be remembered that
low grade stock can subsist on poorer pastures without showing visible
effects.* Nevertheless, many of the cattle on the savannahs of this Colony
have reached the bone-chewing stage, and it ip unlikely that higher grade
stock could keep healthy on such an area.

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AGRICULTURAL JOURNAL OF BRITISH GUIANA.

CX4

Mineral Content of Pasture Grasses.

(per cent, oven-dry weight)

Silica-free

ash

Phosphate

Lime

Potash

Grasses from the Interior
of the Colony :

1. Trachypogon plvmosvs
(N. Rupununi)

1.0

0.03

0.14

0.40

Trachypogon phimosve
(Waranama)

0.83

0.02

0.12

0.29

Savannah pasture
(Shiriri Mts.)

2.4

0.15

0.24

0.50

Legume {Desmodinml)

( Shiriri Mts. )

15.0

0.39

5.00

1.38

Kurasabi Savannah
pasture

i.i

0.02

0.12

0.37

Paramakatoi pasture

1.7

p.05

0.09

0.61

Wynne Grass (N.W.D.)

3.87

0.25

0.48

—

Wynne Grass
(Rupununi )

1.2

0.04

0.10

0.35

Other

■ Grasses for comparison
British Hill pasture

5.85

0.67

0.65

2.66

10.

Falkland Islands pasture 4.56

0.54

0.29

2.20

11.

Molo Kenya

2.35

0.22

0.48

0.77

12.

Mixed Pasture, Govt.
Stock Farm, George-
town

4.75

0.92

0.30

1.61

Wynne Grass from the North West District shows promise of being
more nutritious, as regards minerals, than most of the Rupununi grasses,
but it will be seen from the table that when this grass is planted in the
Rupununi District it shows a very low mineral content. Thus it is unlikely
that the introduction of better grasses would correct the mineral deficiencies
of the savannah pastures. It appears that the soil does not contain the
necessary components in an available form.

In 1924 Sir John Harrison discussed the subject in a critical memoran-
dum (unpublished ) on a report by Mr. J. Mullin (afterwards Commissioner
of Lands and Mines). Mr. Mullin had stressed the deteriorating effect of
excessive inbreeding in the Rupununi cattle, whereas Harrison says :

“ A very remarkable feature of the savannah soils is their deficiency
“ in phosphoric acid. In my opinion it is hopeless to expect fair results

THE SOILS OF BRITISH GUIANA.

181

44 by clearing and planting 50 acres of this land unless the land is very
44 heavily and repeatedly manured with slag-phosphates, say half a ton
44 of the phosphates to the acre. I pointed out many years ago, about
“ 1897, the very adverse effects of the remarkable deficiency of phos-
44 phoric acid in these soils on the nature and composition of the grasses
44 and especially on the cattle which in many cases fail to thrive on them.

44 This deficiency in phosphates is specially characteristic of the Berbice
44 section of the Cattle Trail in the vicinity of which Mr. Melville has
“made unsuccessful results at fattening cattle. The total phosphoric
44 acid varies in these soils from .0001 to ,0005 per cent.— a practically
44 hopeless position.

44 1 am not in full agreement with Mr. Mullin regarding results of
44 inbreeding. I consider that the defective character of many of the
44 cattle is due to scarcity of nutritious food, especially during *heir youth,
44 caused by poverty of the soil generally and especially by its deficiency
44 in phosphoric acid. The soil deficiencies result in defects in quality
44 of the herbage especially in content of proteids, of mineral matters and
44 of the food-accessories classed as vitamins, and thus failure to breed
44 and the production of calves of defective vitality which succumb in
44 early youth is due directly to the poverty of the soil. It is useless
44 expecting high grade cattle to withstand the effects of the very inferior
44 grazing to which even indigenous cattle are apt to succumb.”

This view was also held by Follett-Smith in his report on an investiga-
tion of the soils at Waranama (Ac//. JL, British Guiana, 193), Vol 111.
No. 3, p. 142) but he advocated the regular feeding of bone-meal to the stock,
on the grounds that manuring of pastures would probably prove uneconomic.

There are two main factors involved in any plan to feed minerals to
these cattle. The first is, of course, cost pf transport, and the second is
that it may not be profitable to feed minerals to the low-grade stock, since
the improvement in quality might not be sufficiently great to raise their
market value. On the other hand, if the grade of stock is being raised, ^ the
mineral deficiencies would probably be a limiting factor, and a comparison
between mineral-fed animals and thosb fed on natural pastures snly might
be one between life and death, and thus the cost of transport would be amply
repaid.

5. The Hilly Forest Country Bordering the Savannahs.

In the north the Rupununi savannah region is bordered by the Paka-
raima Mountains, while the southern boundary is the Karawaimentau range,
of which Marudi Mountain is at present the only accessible part. The
northern and southern savannahs are separated by the Kanaku Mountains,
a range which runs roughly East to West. As the natural trend of develop-
ment from the savannah region would be into these hills, their geological
structures and soil types are of considerable importance.

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AGRICULTURAL JOURNAL 0> BRITISH GUIANA.

tX,4.

The Pakaraima Mountains.

The Pakaraima Mountains have generally been regarded as a more or
less barren tableland, or a series of plateaux, consisting entirely of
Kaieteurean Sandstone. Recent geological surveys have shown that within
these mountains are extensive intrusions of basic igneous rocks which give
rise to soils entirely different from those on the gritty Kaieteurean sand-
stone. While the foundation of the range is the Kaieteurean Sedimentary
Series, intrusive sills and large dykes have block-faulted the structure into
a complex patchwork of sedimentary and igneous outcrops. It is significant
that nearly every geological traverse in this region (there are, unfortunately,
only a few) shows large outcrops of basic or intermediate igneouB rock, and
thus the view can no longer be held that the surface rock is almost entirely
sedimentary in origin. The extent to which soils derived from igneous rock
occur is unknown, but the region is well worthy of further investigation in
view of its favourable climate.

There was no opportunity to visit this region during the present survey,
but in 1935 Follett-Smith and Frampton did a 200-mile journey up the Ireng
valley to Tawailing Mountain, across the Yawong River to Kurukubaru, then
over the, Chiung River to Tumong Mouth, and by Chenapowu to Kaieteur.
They report ( Agr . Jl., British Guiana, 1935, p. 155) that, generally speaking
the soils of the Pakaraima range which they examined were of low fertility.
“The open hills consist of buff coloured sands or loams of acidic reaction and
the surface is almost entirely covered with quartz boulders and pebbles. In
other places the hills consist of an acidic red clay covered by a layer of iron-
stone gravel. The mountain tops are usually covered with an infertile white
sand, and on descending one passes through a belt of acidic brown sand and
then a belt of acidic red clay to the creek bed. Many of the mountain slopes
are forest covered, but here and there elevated savannahs are encountered.
Some of these, such as the Echilibar, the Kato, and the Chiung savannahs,
are extensive.”

Two soil samples collected from open elevated savannahs (Kato and
Chiung) were analysed by Follett-Smith, and his results are given in Table
III (Appendix E379 and 380). The analytical figures were interpreted as
follows: “The soil from the Kau> savannah is a markedly laddie sandy
loam. The amounts of organic matter, lime and readily available phosphate
are low. It possesses an adequate amount of potash. The soil from the
Chiung savannah is a markedly acidic sand. The contents of organic matter,
lime, potash and readily available phosphate are low.”

Clay samples were taken from the head of the Tumong River and from
the plateau between Mikroparu and Chenapowu, and the results of their
analyses are also given in Table III (E381 and 382). Follett-Smith says :
“ The soil collected at the head of the Tumong is a highly actdie red day, that
collected on the plateau between Mikroparu and Chenapowu is a markedly
acidic yellow day. Both soils are well supplied with organic matter and
potash, but are deficient in lime and readily available phosphate. While they

THE SOILS OP BttmSH GUIANA.

might produce fair crops under shifting cultivation they are not likely to
stand up to continuous cultivation/'

In the broad valley of the Yawong River between Wandapatoi and Para-
makatoi a considerable area of fertile soil was found. The analytical data
for two samples taken from this area are included in Table III (E377 and
and 378) and there is no doubt that they show the soil to be of excellent tex-
ture and great fertility. No parent rock samples were obtained, but it is
likely that the soil is derived from an igneous intrusion. As far as could
be judged, it occurs in a band five or six miles wide, but its length could not
be estimated.

The Kanaku Mountains.

This range is composed of granitic gneiss and granitised sediments,
with intrusive dykes or sills of unknown extent. In a reconnaissance flight
over the western half of the range it was seen that there are no elevated
savannahs, and the interior of the range consists of rounded hills with steep
sides. Thus the whole range seems to be intersected by valleys varying in
width, and without terracing it would be dangerous to cultivate the hill
slopes. The valleys on the northern side of the range are narrow but the
soil is fertile, as can be seen from samples E504 and 505 in Table III, which
were taken by Sir Geoffrey Evans during his examination of the Moca-Moca
Valley. The hill-wash on the outskirts of the valleys also seems to be
favourable for cultivation, samples E501 — 3 in Table III being from flat land
outside the Kumaka valley. Thus there is room for a certain amount of
development on the flat lands near the mountains and in the narrow valleys
which open to the north. The southern valleys are much wider, but were
considered by Follett-Smith to be less fertille. He says “The soils of the
foothills of the southern side of the Kanaku Mountains do not seem to
possess the degree of fertility associated with those of the north-western
foothills, but are preferable to those of the open savannahs/' He examined
soil samples from the mouth of the Saurap valley and from Toroquara creek,
and found them to be “of fair fertility,” capable of supporting good crops
of padi.

The wide valley of the Rupuriuni River, where it cuts "through the
Kanaku range, offers an attractive field for agricultural development. It was
seen from the air in a reconnaissance flight, and numerous subsidiary
valleys lead in from the hills on both sides. These latter valleys are rather
narrow on the northern side of the range but they are broader towards the
south., Sir Geoffrey Evans visited the main valley, and was impressed by
the potentialities of the soil for permanent agriculture. He took a series of
sol) samples at Makaparima, near a farm belonging to Mr. John Melville, and
the analytical data are given in Table III (E507-514). The samples range
from a light loam to a heavy clay, and are all practically neutral in reaction
(pH 6, 4-6.8) with abundant organic matter and nitrogen. There is, however,
a deficiency of phosphate which would have to be corrected; lime and potash
seem to be adequate.

184

AGRICULTURAL JOURNAL Of BRITISH GUIANA.

EX 4.

An igneous intrusion is marked on the geological maps near Makapa-
rima, and it is probable that the fertile red soil is derived from this basic
rock. This is the only intrusion marked in the Kanaku range, but it is likely
that there are many others which have not been found. A detailed geolo-'
gical survey of this district would be of great value in further soil investiga-
tions, as the petrology of the area may be more complex than is indicated
at present.

Marudi Mountain.

Little is known of the Karawaimentau range, but the geology of Marudi
Mountain, at its south-western end, was examined in 1934 by Dr. D. R.
Grantham. He found the area to be composed largely of intensely meta-
morphosed sediments, with hornblende schists and epidiorites forming the
highest ground. It is believed that the schist and epidiorite represent rem-
nants of beds once lying on the basement gneiss and were invaded later by
biotite granite, which also occurs in the gneiss.

It can be seen from this that the geology of the area is not simple, and
the only rock recorded which would give rise to a t fertile soil is the epidiorite,
the extent of which is not known. A fertile red soil does occur on the
higher parts of the hill (about 1,500 feet) and deep profile pits were avail-
able at gold workings on Dr. Godfrey Davidson’s claims, 18 miles from the
edge of the savannah. One of these cuttings showed 20 feet of rich choco-
late-coloured soil, while the other had about 10 feet of this
soil overlying 10 feet of brown sand. In both places the soil was
lying on gold-bearing quartz gravel, and thus the red soil may have been
deposited as hill-wash. Table III (E533-542) gives the analytical figures
for serial samples from one of these cuttings, which had been opened for
about four months. The fertility of this soil could be judged by the fact
that Dr. Davidson had an excellent garden in a 10-acre forest clearing which
had been cultivated continuously for six years without signs of exhaustion.
It is said that there are many such areas of fertile red soil in the district,
but the hilly nature of the land renders it difficult to judge how useful it
would be for agriculture. It might even be suggested that “controlled
erosion” might be tried, in an attempt to wash the fertile soil from pockets
in the hills on to the flats below.

6. The Berbice River And The Cattle Trail.

The Berbice River.

Sir Geoffrey Evans made a brief survey of the Berbice River as far as
Takama, 100 miles from the mouth. He found that “for the first 20 miles
from the mouth of the river the land consists of lowlying flats typical of the
silts and clays of the coastal sugar belt. Above this the soils become
gradually lighter and more sandy, and the fringe of the riverain deposits,
which are now covered with bush and forest, become narrower. Behind this
stretch of forest the open savannahs stretch in either direction. As far as
Fort Nassau, which is about 50 miles from the sea, they consist of what is

THE SOILS OF BRITISH GUIANA.

185

known as “clay savannahs.” At Torani creek on the right bank of the river
the savannah comes right down to the riverside, and an opportunity was
taken to ride for a short distance over it.” The soil of the wide riverain
flat about 2 miles below Fort Nassau was sampled, and E526 and 527 in
Table IV show it to be a highly acidic loam, with fairly high organic matter
and average nitrogen. Further sampling was carried out at a spot II miles
due east from the bank, where the savannah is higher. Samples E528 — 530,
Table IV, prove that this soil is much more sandy on the surface and,
although the subsoil (3-4 feet) contains a higher percentage of clay, it
does not answer to the term “clay savannah.” Deep ploughing might im-
prove the texture of this soil sufficiently to allow intensive cultivation, or
alternatively orchard crops might be suitable, with irrigation and manuring.

In a bend of the river about 75 miles from its mouth a group of about
20 settlers are cultivating the land, with sweet potatoes as their main crop.
The soil of this district was sampled at Kimbia, and E524 and 525 of Table
IV indicate that it is an acidic light loam of fair fertility.

Another set of samples, top and subsurface soil, was taken in an Indian
reservation about 4 miles up the Wikki creek, which enters the Berbice River
on the right bank opposite Takama. This soil, E522 and 523 of Table IV,
is a highly acidic loam which, though poor in appearance, is being used by
Indians and settlers all along the middle Berbice River. When manure is
applied it yields fair crops, and thus it might respond to a system of crop
rotation which is designed to maintain the organic matter at a high level.

Previous reports on the soils of the Berbice River area include one by
Sir John Harrison, (unpublished) after a visit in 1913, and one in 1931 by
Mr. Follett-Smith (also unpublished ) on a reconnaissance soil survey of
eight plantations which were cultivated by the Dutch settlers in the early
part of the eighteenth century.

In summarizing his findings, Harrison says: “The topography of the
lands immediately bordering the upper tidal reaches of the Berbice River is
such as to ensure their fertility. 1 am certain that with skilful planting
and scientific soil conservation this relatively narrow district will be. found
one of the most fruitful, if not the most fruitful, in British Guiana. It may
be regarded as a river alluvial belt lying on previous sandy clay subsoils pro-
duced by the decomposition of various igneous rocks (gneiss, granite, horn-
blende schist, &c.) in sitv.”

Harrison also visited an abandoned cacao plantation at Kumaka, about
which Mr. B. Howell Jones had eulogized in 1884. He found giant trees
still growing luxuriantly, although they were bearing few pods owing to lack
of pruning. He says : "Now many of these giant cacaos have fallen but
along each fallen trunk new trees, many of them 30 to 40 inches- in diameter,
have sprung. The cacao appeared to me after very careful examination to
be all of one type and to be quite pure in type. It is the strain of type
formerly known as golden Caracas, probably the best cacao in the world.”

lgf, AGRICULTURAL JOURNAL OF RRITISH GUIANA. [X, 4.

Sir Geoffrey Evans visited this estate and found trees sixty feet high with
enormous trunks, but they were covered with Witch Broom.

Follett-Smith carried out a soil survey of the estates of IXarip
Henrietta, Landstroom, Peereboom, Kumaka, Philipsburg, New Caracas,
Doornboom and Osterbeck-, which are situated about 90 miles from the mouth
of the river. He noted four main soil types in the area :

(a) A markedly acidic riverside loam, which appears to be well suited
to the requirements of slow-growing crops such as citrus, cacao,
coffee and coconuts, but is not sufficiently fertile to permit continuous
cultivation of provision crops unless artificial or green manuring is
practised. It occurs in this vicinity as a strip about half a mile wide
on either bank of the river.

(b) A clay soil which is periodically inundated, and supports a flora of

manicole, truli and cocorite palms. It occurs as a strip in the rear
of the riverside silt. In places the bush has been cleared and rice
cultivation is carried on, but there are no facilities for drainage and
irrigation.' <

(c) A broivn lateritic sandy loam which at present is open savannah
Country with occasional forest growth, and it might be suitable for
citrus cultivation. It occurs to the west of Kumaka at a distance of
about 200 yards from the river.

(d) A sand hiU soil type, similar to that found at Wauna Experiment
Station, North West District. Experiments with citrus and other
perennial crops have not been very successful at Wauna, probably
because transport facilities did not permit the regular application of

dressings of manure.

The Cattle Trail.

In 1919 a detailed survey of the cattle trail from Takama on the Berbice
River to Canister Falls on the Demerara River, a total of 92 miles, was carried
out by Mi. A. A. Abraham, and a report on the soil samples was prepared by
Sir John Harrison as a Government paper (Combined Court No. Ill of 1925).
The inspection was done by means of cross lines 5 miles in length cut at inter-
vals of approximately 5 miles on either side of the trail, with intermediate
lines 2i to 3 miles long. The country is a succession of hills ranging from 100
to 600 feet in height, composed of two types of soil, white sand and nut brown
to red sand. The white or grey sands can be divided into two sub-types — Muri
sand and Wallaba sand, both of which are deficient in vegetable matter, are
lacking in retentive power for water, and are therefore of no potential agricul-
cultural value. Inspection of this class of sand from which timber had been
removed showed the most unproductive and barren aspect from a farming point
pt view. The nut brown to red sand is also too deficient in clay to be suitable
for agriculture, and its only agricultural capability seemed to be the raising
of two crops of cassava, yielding a return of 75% less in the second crop com-
pared, with the first.

THE SOILS OF BRITISH GUIANA.

187

Harrison suggests that this sandy area which is crossed by the cattle trail
consists largely of residual quartz-grains derived from the weathering of quarto-
porphyry, or of sand eroded from the Kaieteurean Sandstone formation, which
lies on quartz-porphyry' near the Demerara River sections of the trail. His
conclusions on the soil survey are: “ Dealing as a whole with the soils collected
“ during the cattle trail survey they can only be described as quartz sand pass-
“ ing into very sandy soils, and into mixtures of quartz-sand with leached-out
“ lithomarge or kaolin. The soils have been thoroughly impoverished of the
“ constituents necessary for soil fertility and, as savannah soils elsewhere in the
“ Guianas were described by Humboldt, their areas are among the “ Deserts of
“South America” I can describe them only as hopelessly barren except in
“cases where their subsoil waters may be held up at depths of 18 inches or so
“ trom the surface. In such latter cases certain forest trees may flourish,
“ while economic plants which require for their growth a very light soil may do
“ fairly well for a short period ”.

Abraham also mentions the lowlying banks of the streams which flow
through the country. These form narrow strips of land, the greatest width
being only 400 feet. No soil samples were taken from these areas, as they
were considered to be impracticable for farm lands, owing to the fact that they
are flooded for the greater part of the year.

With regard to the soils of the forest country between Kurupukari and
Surama, Harrison had to rely on the observations of others, and he concludes
that large areas along the trail in the Burro-Burro Valley are composed of sand
and clay silt which is fertile and well watered. But these low places are 10
deeply flooded during the rainy season that even the passage of cattle is pre-
vented, and in the absence of drainage they would be unsuitable for cultivation.
This periodical inundation could be remedied by thoroughly clearing the Burro-
Burro River and its tributaries of the innumerable fallen trees which obstruct
their courses and back up the water on to the adjoining valley lands.

7. The North West District.

The only definite information available on the soils of the North West
District was published (Chem. Bull. No. 1. Dept, of Agri.) in 1930 by Follett-
Smith, who made a detailed soil survey of an area of 156 square miles, bounded
by the Barima, Aruka, Aruau and Yarakita Rivers. He found three main
soil types: “pegasse” (i.e., peat) swamps covering 103 square miles; sand hills
covering 40 square miles; and lateritic clay soils covering 13 square miles.
This survey was carried out with a view to colonisation by the British Guiana
Gvverpment, but the results of the topographical survey indicated that drainage
of the swamp area would be a matter of extreme difficulty and great cost. The
pegasse soils were accordingly ruled out of consideration as far as widespread
Settlement was concerned. The lateritic clay type, though more, suitable, occurs
to a vary limited extent, and on the hillsides it is so shallow that cultivation
would not be advisable. The sand hill soil is an acid sand of low organic
matter content, and experience has shown that under continuous cropping its
fertility is lost within two or three years. An experiment station was set up

188

AGRICULTURAL JOURNAL OP BRITISH GUIANA*

[X, 4.

on this soil type at Wauna, near the Government Station of Mabaruma, and
this has shown over several years of experiment that even perennial crops such
as citrus, coconuts and oil palms would require heavy applications of manure
in order to produce good crops.

This soil investigation was carried out on land relatively near the coast,
where the main problem in agricultural development would be drainage. Yet,
of the 7,500 square miles which are included in the North West District, less
than 2,000 square miles arc coastal swamps and hills. Thus there is over
5,000 square miles of territory which is geologically allied to the interior of

the Colony as distinct from the coastal belt. The soils of the interior of

the North West District have not been examined in detail, since marketing
of produce would be extremely difficult on account of transport costs. The
officers of the Geological Survey report that there are large areas of
gneissose granite with numerous intrusions of both acid and basic rocks,
and their observations indicate that there may be fairly extensive areas
which would respond to scientific methods of cultivation. There are
numerous Indian gardens, chiefly on the granite, and it is significant that
gold workers can “live on the country” for months at a time without
suffering from the nutritional diseases which tend to occur in other parts of
the forest belt.

Communication in this area is much easier than in the centre and souih
of the Colony, as the rivers are navigable for small boats and free from rapids,
and on the whole it is possible that agricultural settlement based on an indus-
trial centre might be successful. Without local markets it is very doubtful if

colonisation would be economic, unless it was carried out on a scale large

enough to bear the cost of greatly improved transport facilities.

Acknowledgments.

Most of the geological information was supplied by Mr. S. Bracewell, Di-
rector of the British Guiana Geological Survey, to whom thanks alre due for
much helpful advice The soil analyses were carried out by Mr. C. L. C.
Bourne, Assistant Chemist, Department of Agriculture, and credit is due to
him for the expeditious manner in which they were completed.

THE SOILS OF BRITISH GUIANA.

189

Appendix.

Notes On Analytical Methods.

(1) Mechanical Analysis. Robinson’s method (Imp. Bur. Soil Sci. Tech.
Comm. 26, 1933) was employed, the silt being calculated by subtracting
from 100 the sum of the sand fractions, clay, loss by solution and organic
matter.

In the analysis quoted from Follett-Smith’s survey the Index of Tex-
ture was determined by Hardy’s method (Jr. Agr. Sci. 1928, p. 262).

(2) Reaction (pH) Quinhydrone electrode, using 10 gms. soil in 40 ccs. water,
left standing overnight. The KC1 exchange reaction was also determined
but is not given in the tables.

(3) Organic Matter =- r / r carbon x 1.724. The carbon was estimated by
Hardy’s wet combustion method (Jr. Apr. Sci. 1929, p. 727).

(4) Nitrogen. Kjeldahl’s method, using as catalyst a mixture of copper sul-
phate, potassium sulphate, and selenium.

(6) Available Phosphate. Truog’s method (Jr. Amer. Soc. Agron. 1930 p.
874). The results are expressed as parts per million air-dry soil.

(6) Exchangeable Bases. Leaching with N 2 acetic acid, the results being
expressed as milligram equivalents per 100 gms. air dry soil. Lime
(CaO) was estimated as oxalate, and potash (K0) as the chloroplatinate.

Soils of the Essequibo Basin .

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MINERAL DEFICIENCY AND CATTLE RAISING IN
BRITISH G HI ANA.

D. W. DUTHIE, PH.D., F.l.c.

Chemist, Department of Agriculture.

1. The Rupununi Savannahs.

The savannah country which borders Brazil between latitude 2* and 4*
N. covers some 5,000 square miles, and is ecologically part of the immense
savannah land of Northern Brazil. The Kanaku mountain range, rising to
4,600 feet, divides the area equally, and gives rise to a network of creeks
and streams which eventually join the two water systems of the region, the
Takatu and Rupununi rivers. Thus the area is well-watered, and even in
the dry season, when the rivers are low, the cattle can obtain sufficient
water, while Ite palms ( Mauritia flexuosa) and low bush along the creek
beds provide shade for the animals during the day.

Climatically, therefore, this area is suitable for cattle, and at present it
carries over 50,000 head. Grazing is not controlled to any great extent, and
the prevalence of bone-chewing shows that there is a serious deficiency of
phosphate in the grasses. This is confirmed by chemical analysis, and
Tables I and II show that these pastures are even more deficient in lime and
phosphate than areas in Kenya, South Africa, Falkland Islands and the
United States of America in which mineral deficiency proved to be the
limiting factor in stock raising. The grass from Mt. Shiriri which shows
a high lime content (5%) is probably associated with a narrow outcrop of
marly rock, and the area covered by grass of this type is too small to be
important to the cattle industry as a whole. Apart from this single species,
the grasses of the savannah are deficient in minerals to an extent which
would reader intensive stock-raising almost impossible, and improvement of
breed, except possibly by Zebu types, would lead to numerous diseases
which are known to be caused directly or indirectly by lack of minerals.

The samples of Wynne grass in the same table show the result of in-
troducing new grasses. This species was planted in the North West Dis-
trict and gave 0.5% lime and 0.3% phosphate. The same planted in the
Rupununi District gave 0.1% lime and 0.04% phosphate. This indicates
that the mineral deficiency cannot be corrected by introducing new pasture
grasses, and soil analyses have also shown that the necessary elements are
not present in sufficient quantity.

Experiments in South Africa (15) and in Kenya <"6) proved that
deficiencies of lime and phosphate can be corrected by regular feeding of
bone meal, or by the application of fertilizers to the grazing areas. In
this connexion it is interesting to note that as early as 1897 Sir John

MINERAL DEFICIENCY AND CATTLE RAISING IN BRITISH GUIANA. 193

Harrison realized that phosphate deficiency is an important factor in the
eattle industry of the Rupununi District, and he advocated the application
of basic slag at the rate of 6 cwts. per acre. With a rainfall of over 60
inches per annum, falling mainly in 6 months, this method of supplying
phosphate would be wasteful, but, apart from this, the great transport
difficulties render even the feeding of bone meal an expensive item. River
communication with Georgetown is so difficult, on account of rapids, that
the freight charges to the Rupununi savannahs average 10—12 cents per lb.

As a result of these transport difficulties, the Rupununi ranchers have
not been able to fence their lands adequately or to correct the mineral
deficiency. The open range system has worked surprisingly well, since the
cattle have multiplied from a handful introduced prior to 1900. They live
in a semi-wild state, but only a few are killed by jaguars and snakes. The
grasses are quite tender when they spring up after burning, but they
rapidly become fibrous and unpa'a table as they approach maturity.

Taking the difficulties into consideration — poor breed, lack of fencing,
lack of minerals, and lack of care for the calves — the animals on the range
are in reasonably good condition. Before they reach the Georgetown mar-
ket, however, they are driven through 180 miles of forest or scrub bush, in
which the grazing is too limited to provide more than a starvation ration.

II. The Cattle Trail.

Prior to 1919, the only market for Rupununi animals was in Brazil, but
in that year Mr. H. P. C. Melville was authorised by Government to
demarcate a trail from Annai, at the Northern end of the savannahs, past
Kurupukari and Canister Falls to Takama on the Berbice River. For the
first few miles after leaving Annai the trail is mainly in savannah country,
but near 180 miles it enters the forest, and then, apart from a small
savannah at Surama it runs through thick forest to about 40 miles. The
rest of the trail to Takama is in relatively open country, with low scrub
bush.

A careful study of the soils of the cattle trail was made by Sir John
Harrison (13), who summarized his findings as follows: —

“Dealing as a whole with the soils collected during the Cattle Trail
"Survey they can only be described as quartz-sand passing into very sandy
“soils and into mixtures of quartz-sand with leached-out lithomarge or kaolin.
“The soils have been thoroughly impoverished of the constituents necessary
“for soil fertility, and as savannah soils elsewhere in the Guianas were
“described by Humboldt their areas are among the Deserts of South
“America.”

Thus the problem of providing good grazing for the animals during
their passage through the trail is one of the greatest difficulties. Numerous
paddocks have been established, but the cost of clearing the forest and of
fencing are too high to permit rapid improvements. For some years the
trail was managed by the Rupununi Development Company, on .a decreasing
grant from Government. Since the end of 1934, the trail has been directly
n od et Government control, managed by the District Commissioner, whose
varied duties allow him little time for intensive supervision.

196

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 4.

With these difficulties in view, it is not surprising that the animals are
driven through the trail under starvation conditions. The soils are too poor
to support rapid growth of indigenous grasses and the paddocks are eaten
out and trampled down by the first drive of the season. This might be
corrected by controlled grazing in larger subdivided paddocks, but that would
require more supervision and higher maintenance costs, and the market
value of the animals in Georgetown is too low to justify this.

Since the main requirements of the animals on the trail are protein and
carbohydrate to provide energy, the mineral content of the trail grasses is of
secondary importance. It is here that new grasses would be of great
value, but the experimental work would necessitate more supervision than is
possible under the present system.

III. The Intermediate Savannahs.

The term '"intermediate savannahs” is applied to those grazing areas
which are situated in the Berbice, Canje, Ahary, and Corentyne river
systems, sufficiently far from the coast to be clear of the clay and pegasse
soils which consitute the chief sugar and rice lands.

An intensive examination of ihe Waranama ranch, about 100 miles up
the BeVbice River, was made in 1930 by Bone, Follett-Smith, and Martyn.
Their reports (2, 7, 14) show that the feeding conditions in this area are
too poor to support breeding stock (see analyses in Table III). Bone (2)
mentions that animals from the Rupununi savannahs are kept on this ranch
until they are required for the Georgetown market. Thev arrive at
Waranama in a tired condition after their journey through the trail, but
they soon recover from this and are then in fair condition. They retain
this condition provided that they a^e not kept on Waranama for more than
a few months, but if there is delav in despatching them to the market they
lose condition and become emaciated.

Bone further reports that one hundred head of cows and. heifers were
transferred to Waranama from the Rupununi District, in an attempt to
keep breeding stock on this ranch. They lost condition rapidly and died.
There is nothing in the analytical figures in Tables I and III to explain why
animals breed quite rapidly on the Rupununi savannahs, but become
emaciated if they are kept for long periods at Waranama.

In this connexion, one point in Bone's report is of particular interest.
Mr. Haly, then Manager of the ranch, stated that animals graze on burned
areas for a few days only, and that they leave these areas while there is still
a good spring of young grass. In a recent conversation, Mr. Haly men-
tioned that he had attempted to force some animals to graze a burned area
by fencing them in. After about a week, the animals would not eat, and
thus his attempt to institute close grazing on a rotational plan was not
successful. Bone suggests that the animals lick the ash in addition to
cropping the young grass, and that their taste for the grass disappears when
the ash is exhausted.

ktlttfeRAL DfiftCIENClf AND CATTLE RAISING IN BRITISH GUIANA. }{)?

On Table III analytical figures are given for grass at different stages
of growth.. These samples were taken from an area in which the forest
had recently been cleared, and the grass is much higher in mineral content
than that of the open savannah. There is no definite drop in the contents
of lime and phosphate up to six weeks of age, but the nitrogen content of
the youngest grass is much higher than that of the others. Palatability and
protein content may thus be of some importance but this is not sufficient to
account for the unsuitability of the area for breeding stock.

A possible solution of the problem is found by comparing the “effective”
grazing areas of the Rupununi savannahs with those of Waranama. The-
Rupununi Development Company holding on the Southern savapnah covers
2,000 square miles, on which there are at present some 40,000 head of cattle.
This works out at 20 animals per square mile or one animal to 32 acres,
which seems to leave room for heavier stocking. But the cattle graze almost
exclusively on the grass along the creek beds, where conditions are more
suitable for rapid growth, and they can scarcely be persuaded to leave these
areas even when they are over-grazed. The samples on Table I were
taken from higher land, and, although no analyses are available for the
“creek bed” grasses there are indications that the soil is less barren on these
low-lying lands.

In the Rupununi savannahs the proportion of creek bed areas is less
than one hundredth of the whole, but, taking this figure as a maximum, we
have one animal to 0.32 acres of “effective” grazing. This is definitely

overstocking with the herd at its present size, particularly as this pasture

is available only in the drier parts of the year w T hen the floods recede.

This point has been emphasized by Turner (16) who estimates that less than
one-fifth of the grazing area is of value. This, however, must include areas
of higher land which are grazed for only a tveek or so after burning, and
therefore cannot be regarded as “effective” grazing, since the animals

utilize # them only as a last resort. The analytical figures suggest that no
animal could exist on the pastures which constitute the bulk of the grazing,
and the reason why the cattle always look their best in dry weather may
be the fact that the creek bed grasses are available at that time.

At Waranama most of the land is undulating, with a very small area of
creek bed grazing land, say one five-hundredth of the total area (i.e., 100
acres in 80 square miles). This means that when a drive of 500 steers
arrives from the Rupununi savannahs at the beginning of the dry season the
animals find 100 acres of lush grass in addition to the poor grasses of thej
higher lands (the ranch is now used only for resting steers on their way to
the coast). This creek bed area is grazed at the rate of 5 head per acre*
and insufficient to let them regain condition for a time. When this grassf
is eaten dowm -they will not leave the creek beds except for a few days*
grazing on a freshly burned area of higher land. As a result of this they
lose condition and eventually become emaciated. It is probable that the
breeding experiment referred to above was in addition to the ordinary carry-
ing capacity of the ranch, and thus the animals could only obtain the grass
of the higher lands.

i&i AGRICULTURAL JOURNAL OF BRITISH (lUiANA. 4.

We have thus reached the conclusion that the pastures on the higher
lands of the Rupununi and Berbiee savannahs are valueless for grazing, prin-
cipally, it would appear, on account of their extreme deficiency of lime and
phosphate. A supplementary mineral ration might render these available
for grazing, and so greatly increase the “effective" grazing areas. On account
of the high cost of transport, mineral rations are at present out of the
question on the Rupununi savannahs, but the easily accessible Berbiee
savannahs present a better prospect in this respect Experiments are now
being started on two Berbiee ranches in which steers which have come
through the trail will have access to a mixture of bone meal and salt in an
attempt to recondition them for sale in Georgetown. The chief difficulty
will probably "he the wildness of the animals, and there may be some difficulty
in persuading them to take the minerals.

IV.— The Coastlands.

Numerous papers on the livestock problems of the coastlands (1, 8, 4, 6,
9, 10, 11, 12) have shown that there are great difficulties with fencing and
drainage. Fencing is complicated by flooding during the wet season, when
the animals must have higher land on which to rest, and many areas of
normally good grazing are practically useless for long periods every year.
The high cost of drainage on the low-lying coastlands would not be repaid
by beef cattle, and even dairying is heavily handicapped by this expense.

Table IV gives analytical figures for several species of coastland grasses,
the mineral content of which is much higher than that of the interior savannah
grasses. While mineral supplements would probably be of value in fattening
stock for the market, there is no evidence of acute deficiency on the average
pasture. At the Government Stock Farm a mineral mixture is regularly fed to
all stock, and the high lime and phosphate contents of the pasture grasses is a
direct result of this. Most of the analyses recorded are of samples from
Government land, but there are no symptoms of mineral deficiency on any of
the coastal grazing areas. Thus cattle-raising on the coast is not handi-
capped by lack of minerals, and the factors which limit the industry are out-
side the scope of this discussion, namely, fencing, communal agistment areas,
and drainage.

It is noticeable that some of the coastland grasses are higher in minerals
than others, but it should be pointed out that a pure stand of a single species
would not be advisable. As the seasons vary there is a succession of
pasture species which maintain a good sward, and one single species would
not flourish under the rapid alternations of flood and drought which are
accentuated by the heavy clay soils. The variation of mineral content
through the year is shown in Table V, in which Follett-Smith (8) shows the
analyses of monthly samples from a new paddock in the Government Stock
Farm. This pasture is lower in minerals than the grasses from the Stock
Farm in Table IV, since this area had not been grazed by mineral-fed
animals. The somewhat surprising regularity of mineral supply is due
partly to a fairly even distribution of rain throughout the year, and partly
to the succession of pasture species which balance the climatic variations.

MImsial deficiency and cattle raising in British guiana. 199

References.

(1)

Bone, T. (1930).

Cattle in the coastal belt. Agric. J. British
Guiana, Vol. Ill, p. 35.

(2)

— (1930).

Investigation of ranching problems of the
Waranama Savannah, Berbice River. Agric.

J. British Guiana, Vol. Ill, p. 160.

(3)

— (1934).

Cattle on the coast. Agric. J. British
Guiana Vol. V, p. 200.

( 4 )

Dash, Prof. J. S.

(1935). Livestock problems in British
Guiana. Agric. J. British Guiana, Vol. ¥§§, VI

p. 100. '

( 5 )

Economic Advisory

Council (1931). Sixth Report of

the Committee on the mineral content of
natural pastures. H.M. Stationery Office,
London.

(6) Follett-Smith, R. R. (1930). Minerals in the pasture

grasses of British Guiana. Agric. J.
British Guiana, Vol. Ill, p. 39.

(7) — (1930). The Report of an investigation of

the soils and of the mineral content of
pasture grasses occurring at Waranama
Ranch, Berbice River. Agric. J. British
Guiana. Vol. Ill, p. 160.

(8)

(1934). Divisional Reports, Department
of Agric., p. 100.

(9)

Fraser, H.

(1935). Dairy Cattle in British Guiana.
Agric. J. British Guiana. Vol. VI, p. 71.

(10)

and Bone, T. (1935). An experiment
with dairy cattle in British Guiana. Agric.
J. British Guiana, Vol. VII, p. 222.

(11)

—

(1938). A grade dairy herd. Agric. J.
British Guiana. Vol. IX, p. 153.

(12)

Fulton, A.

(1931). Fencing and* its significance in
relation to local livestock problems. Agric.
J. British Guiana, Vol. IV, p. 5.

(13)

Harrison, Sir J. B.

(1925). Memorandum on the soils of the
Cattle Trail. Combined Court of B.G.

Sessional Paper No. 11/1925.

§06 AGRICULTURAL JOURNAL 6f BRITISH GUIANA. [X 4.

(14) Martyn, E. 8. (1981). A botanical survey of the

ftupununi Development Company’s ranch
at Waranama, Berbice River. Agric. J.
British Guiana, Vol. IV, p. 18.

(15) Theiler, Sir A., Green, H. H., and Du Toit, P. J. (1924)

Phosphorous in the livestock industry. J.
Dept, of Agric. Union of South Africa.
Vol. 8, p 460.

(16) Turner, H. E. (1938). A short history of the Rupu-

nuni Savannahs with special reference to
the livestock industry. Agric. J. British
Guiana. Vol. IX, p. 230.

Analysis of Grasses*

(Figures are per cent, oven-dry weight).

Table I.

Rupununi Savannah Grasses.

Lime

(CaO)

Phosphate

(P,0,)

Nitrogen

Mixed pasture, Mt. Shiriri

0.24

0.15

Legume ( Desmodium ?) Mt. Shiriri

5.00

0.40

Mixed pasture, Kurasabi

0.12

0.02

Mixed pastua'e, Paramakatoi
Trachyoogon plumosus , Bon Success

0.09

0.05

0.14

0.03

Meltnis minutiflora (Wynne grass)
Rupununi District

1.10

0.04 !

North West District

0.48

0.26

•Abstracted from various papers quoted in the text and from Departmental records.

MINERAL DEFICIENCY AND CATTLE RAISING IN BRITISH GDIANA. 201

Table II.

Other Grasses for Comparison.

Lime

(CaO)

Phosphate

PsOfl

Nitrogen

Pasture, Molo, Kenya (mineral
deficient) ...

0.48

0.22

0.95

Pasture, Nakuru, Kenya (mineral

deficient) ...

0.41

0.30

0.89

Prairie hay, Minnesota, U.S.A.

(mineral deficient) ...

0.58

0.23

• • •

Pasture, Falkland Is. (mineral

deficient) ...

0.29

0.54

1.95

Veldt pasture, S. Africa (mineral
deficient)

Sampled 10th Nov. 1010 ...

0.60

| 0.31

1 3.15

„ 15th Jan. 1020 ...

0.22

0.50

i 2.21

„ 19th April „

0.11

0.46

1 0.78

„ 8th June „

0.09

0.59

0.64

Poor hill pasture, Great Britain ...

0.56

0.60

2.54

Cultivated pasture, „ „

1 1.00

0.74

2.83

AGRICULTURAL JOURNAL OP BRITISH GUlANA.

Table III.

Grasses of Intermediate Savannahs.

tS.4.

Pasture, Yawakuri, Cattle Trail
Scfena microcarpa , Orealia, Corontyne I
River

A.tonopus attniurituH f, Corentvne River
Stenophyllus conifer us, Oorentyne River
Mixed pasture, Toorani, Berbice River
A.ronopus attenuatus, Waranama, Berbice
River

Cupriola d net y ton , Waranama, Berbice
River f

T-amcum barhinode , Waranama, Berbice 1
^iver

Aronopus aureus, Waranama, Berbice
River

“Pan Grass” Waranama, Berbice River
(mixed pasture in water holes)
Trachypoyon phonos u s, Waranama, j

Berbice River I

1 week after burning \ bush
ft weeks after burning r recently
ti weeks after burning * cleared [

Open savannah, mature grass 1

Open savannah, 1 weeks after burning

Lime

CaO

Phosphate

(P a O«)

Nitro-

gen

0.14

0.01)

1.19

o.o:>

0.03

0.04

0.1.1

0.07

0.54

0.10

0.07 I

0.87

0.00

0.12 i

0.7(5

0.17

0.01

0.50

0.32

0.14

1.09

0.25

0.15

1.31

0.20

0.10

0.47

0.21

0.09

0.55

0.12

0 33

2.1(5

0 Oil

0.22

1.11

0.17

0.34 i

1 H

0.12

0.02

0.48

0.12

0.04 J

0.74

kiNEfcAL tmcmtc? AND CATTLE RAISING IN BRITISH GOlANA. 203

Table IV.

COASTLAND GRASSES.

Government Stock Farm.

Mixed pasture

Capnola dactylon (Bahama Grass)
Panicntn barbinode (Para Grass)
Conimelhia nudiflora (Zeb Grass)
Asystasia gangetica ( Demerara Primrose)
Pa spalu m conjugation (Sour Grass)
Paspalmn virgatinn (Razor Grass)
Indigofera endecaphylla
Tripsacnm lax urn (Guatemala Grass)
Georgetown Experiment Station .

Penniaetum pupnrenm (Elephant Grass)
Ahjsicnrpus naginatas (Horse Weed)
Phaseohts catcaratus (Rice Bean)

Uba canc stalks
Uba cane leaves
. 1 nd ro/Higon nodosus
Mahaica Savannah.

Homalocenchrus hcuandrits (Fine Grabs)
Essequibo .

Phaseolus semi erect us

Kitty.

Dextmodnon barbaium

Lime

( CaO )

Phos -

phate

( P a 0 6 )

0.30

0.02

0 40

0.22

0.25

0.22

0.03

0.28

0.82

0.45

0.86

0.45

0.05

0.81

0.15

l 0.58

0.28

0.03

1.15

0.55

0.62

i .37

0.07

trace

0.28

0.76

0.26

0.17

0.18

0.13

1.53

0.82

0.85

1 0.47

Nitro-

gen

1.38

1.18

1.21

1.80

3.83

2.07

2.20

3.01

1.03

0.85

3.36

3.45

0.00

1.15

1.16

1.21

2.78

315

204

AGRICULTURAL JOURNAL Ofr fefeiTISit GUIANA. [X, 4.

Table V.

Seasonal Variations in Coastland Pasture.

1 Lime
(CaO)

^ Phosphate

1 (P,OJ

Nitro- '

(JEN

Mixed pasture, Govt. Stock Farm (new

paddock)

Sampled 3. 8.33

I 0.47

0 11) i

1 1.19

12 . 11.33

0.43

0. 15

i 1.18

3 . 10 . 3 :$

0.35

0.41)

1.2S

13.11.33

0 61

0.41)

1.37

4.12.33

0.3'.)

0 50

1.31

4. 1.34

0.34

0.42

1.01

0. 2.34 1

0.14

0.45

1.51

9. 3.34 l

0.31

0.48 1

1 12

4. 4.31

0.35

0.13 |

1.23

11. 5.34

0.43

0.17 1

1.07

3. 6.34

0.50

0.19 |

1.51

4. 7.34 |

0.4D

0.53 1

1.46

IRRIGATION-MANURIAL TRIALS WITH SUGAR CANE
ON FLOOD-FALLOWED FliONTLAND,

C. HOLMAN B. WILLIAMS, M.A , A I.C.T A., Dip. Agr.,
Sugar Agronomist and Plant Breeder , Department of Agriculture .

Introduction.

The general layout of British Guiana cane lands has been described by
Deerr (1921), Williams (1931), Follett-Smith 0933) and Cooper (1937), and
it is assumed in this paper that readers are familiar with such peculiarities of
the layout as affect the subject under discussion. Suffice it to say that, owing
to the flat, low-lying nature of the land, the irrigation methods in vogue in
other cane countries are hardly feasible here.

Although the total precipitation in most years would be ample for the
production of satisfactory crops, its distribution is faulty, and dry periods
frequently occur when the rainfall for twelve to eighteen successive weeks
may average less than an inch per week. At such times recourse is had to
irrigation, which is effected by cutting the dam bed of a given field facing the
main navigation canal and allowing the water to flow in. In some instances
it is possible thus to cover the internal beds by gravitational flow, but more
usually the cut has to be closed when the water ceases to flow in and a portable
pump (Skinner, 1936) is used to complete the operation.

The water, on entering, first fills the drains and collectors, then gradually
rises over the lower parts of the internal beds and finally covers the entire field,
except the highest portions of the peripheral beds which act as retainers.
With a combination of gravity flow and the usual 6,000 gallons-per-minute
pump, the complete flooding of a 10-acre field will take from ten to eighteen
hours.

The water is allowed to remain undisturbed for twelve to twenty-four
hours and is then released into the main drainage canal. The period of reten-
tion is shortest in young plants and or on lighter soils and longest in ratoons,
older canes and 'or on stiffen soils. It takes from ten to fifteen hours com-
pletely to run out of a ten-acre field. Thus, the highest portions of the
cultivated soil remain covered from twelve to twenty-four hours while the
lowest parts may be covered for as much as 24-36 hours.

The frequency with which such irrigations are given varies, according to
the number of pumps and the amount of water available, from^estate to estate,
but one may say that, in general, an effort is made to treat any given field at
least at monthly intervals during dry spells,

206

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

tX, 4.

The question having arisen as to whether more frequent irrigations are
desirable and whether the cane could advantageously use more nitrogen if
irrigated more frequently, tests were laid down on four estates to throw some
light on the matter.

The Experiments.

Topographical conditions and the method of irrigation precluded the use of
small replicated plots within a field. Three fields were therefore used on each
estate. Each of the three fields was irrigated according to a definite schedule,
arbitrarily denominated ‘low', ‘medium’ and ‘high’, i.e. : —

Low : Irrigated whenever the rainfall for the preceding 28 days

totalled less than 2 inches.

Medium : Irrigated whenever the rainfall for the preceding 14 days
totalled less than 2 inches.

High : Irrigated whenever the rainfall for the preceding 7 days totalled

less than 1 inch.

As the experiments were conducted on four estates, there were four fields
at each irrigation level. In each field, replicate plots were laid down to compare
the effect of 3 and 6 cwt. of sulphate of ammonia per acre, and the fields were
treated and harvested as plant canes, first and second ratoons.

The dates of planting and harvest for the respective estates are shown in
Table I.

Table I.

Dat»s of Plavting avd Harvests of Irrigation-Mavvrial Trials.

Estate

Fields \

Planted

Plants

Harykmep as

1 Fiist Ratoons

| Second Ratoons

Date

Age,

Month.

Date

Age,

Months

Date

Age,

Months

Skeldon

119/80

1‘21/MI

123/80

29 11.30

6 IV. 37

13]

9, VIII. 38

r27.VII.39

111

Port

Mourant

2 P.M L

a p.m.l,

4 P.M.L,

12.X 11 35

| 3 II 37

13]

•24 11 38

12]

24.11.39

Roae

Hall

oocri

HHM

4.V1130

4.V37

8.IY.38 j

22.111 39

Bath

21 D,

20 1)

19 D.

17.YIT.36

•22 YII.37

12]

21 .VII. 38

29.VI.39

From the above it will be seen that trials at the four sites were not planted
and harvested simultaneously. In consequence the canes at the various sites
encountered the dry periods at different ages. Since, in commercial practice,

IRBIGATJON-MANURIAL TRIALS WITH SUGAR CAKE. 207

planting Is carried on for some two-thirds of the year, it was felt that
something nearer a general answer would be secured by having the
experimental blocks (a group of three fields on a given estate) harvested at
different dates.

The number of irrigations given the various fields and the rainfall at the
four estates are compared in Table II.

Table II.

RainfaU and Number of Irrigations at the Various Sites.

Plants

Frequency

Rain- j

Estate.

fall

No. of

;

Irrigation

during

Irriga-

Cycle

tions.

Low

Skeldnn

Medium

80.33

High

1-8

Low

Port Monran'

Medium

1 72.41

High

1 10

Low

l o

Rove Hall

Medium

42.14

High

JiOW 1

Bath

Medium

88.13 1

Hi eh

First

Ratoons

Second Ratoons

Rain-

, Rain-

fall

| No. of

fall

No of

during

! Iniga-

during

Irriga-

Cycle.

i tions.

Cycle

tions.

1 in.

140.92

81.07

.')

01.00

1 102.9.')

120.73

93.00

1 7

1 I*

124.28

92 3.')

The Results.

The varying frequencies of irrigation were without definite differential
effects on the cane quality and it will suffice if we consider only the yields of
cane, as shown in Table III.

208

AGRICULTURAL JOURNAL OF BRITISH GUIANA#

[X, 4#

Table III.

Effect of Varying Irrigation Frequencies on Cane Yield .

Estate.

Skeldon

Port

Mourant

Rose Hall

Bath

Combined

Results

Tons Cane per Acre

Skeldon

Pork

Mourant

Rose Hall

Bath

Combined

Results

Frequency

Irrigation.

Plants

First Ratoons

Second Ratoons

3 cwt.
S.A.

6 cwt.
S.A.

3 cwt.
S.A,

6 cwt.
S.A.

3 cwt.
S.A.

6 cwt.
S.A.

Mean.

Low

51.25

54 51

52.88

31 38

34.01

32.69

27.15

35.08

31.11

Medium

41.50

49.38

45.44

29.15

32.74

30.94

24.90

3156

28.23

Hi«h

46.89

52.58

49.73

29.70

29.81

29.75

18.96

25.75

22.35

Low

53 46

54.09

53.77

36.26

44,61

40.43

24.21

29,02

26,61

Medium

48 48

49.06

48.77

36.99

43.20

40.09

25.99

31.16

28.64

High

47.98

47.74

47.86

40.68

48.31

44.44

26.74

31,86

29.30

Low

28.92

26.33

27.62

21.18

25,91

23.54

24.06

28.46

26.26

Medium

22.89

23.71

23.30

24.52

27.51

26.01

25.27

30.55

27.9!

High

27.30

29.89

28.59

, 29.91

35.68

32.79

29,64

32.77

31.20

Low

41 31

41.30

31.63

' 31.77

31 70

29.70

31.48

.‘10.59

Medium

35.14

41.87

38.50

28.93

33.42

31.17

27 51

31.77

29 64

High

40 30

43.33

41.81

24.69 ,

24,36 (

24.52

25.01

24.54

24 77

Low

43.73

44.06

43 90

30.11

34.07

32.09

26.28

31.01

28 64

Medium

37.0!

41.01

39 01

29.90

34.22

32.06

25.90

31 26

28.58

High

40.62

43.39

42.00

31.22

34.54

32.88

25.09

28.73

26.91

Summary of i Effectn. ,

I 1

In favour of ‘Low’ , Diff. not significant I In favour of ‘Low’

Diff. not significant

Diff. not significant
Diff. not significant

In favour of 1 Low ’

Diff. not significant ( Diff. not significant

In favour of ‘High’ j Diff. not significant
In favour of 4 Low 1 , In favour of 4 Low ’

Diff. not significant | Diff. not significant

In view of the above it must be concluded that, under local conditions,
there is no advantage in irrigating cane more frequently than once in 28 days
(when the rainfall in that period has not exceeded 2 in.).

No support was found for the suggestion that with more frequent irriga-
tion heavier doses of nitrogen could advantageously be used.

IRRIGATION-MANURIAL TRIALS WITH SUGAR CANE.

209

Acknowledgments.

Grateful thanks are expressed to Mr. R. R. Follett-Smilh who assisted in
designing the tests, to the sugar estate authorities concerned for their co-opera-
tion, and to the Staff of the Sugar Experiment Station for their collaboration.

References.

1. Cooper. St. G. C. (1937’). Cane Growth Studies in British Guiana. — Agric.

J. Brit. Guiana, VIII, pp. 6 — 7.

2. DEERR, N. (1921). Cane Sugar, p. 126.

8. FOLLETT-Smith, R. R. (1933). The Flood-Fallowing of Cane Fields
in British Guiana. — Trop. Agric., X, p. 91.

4. Skinner, C. R. (1936). The Screw or Propeller Pump as used for Irriga-

tion and Flood-Fallowing in British Guiana. — Agric. J. British Guiana.
VII, p. 165.

5. Williams, C. H. B. (1931). An Experiment with Bamboo Underdrainage

for Sugar Cane.— Agric. J. Brit. Guiana, IV, p. 33

RECENT INTRODUCTIONS OF ORNAMENTAL PLANTS IN
THE BOTANIC GARDEN, GEORGETOWN.

E. B. MARTYN, B.A., A.I.C.T.A.,

Botanist and Plant Pathologist

and

Superintendent, Botanic Garden.

The introduction of new ornamental plants to the Botanic Garden with a
view to increasing its beauty and adding to its interest is an important item
in the general management of the Garden. Introductions are effected in a
number of ways, and generally on an exchange basis. Sometimes a selection
of seed is sent by allied institutions with the hope that it may yield material
of value and a request made for other varieties, usually specified, in return.
The Garden publishes a seed exchange catalogue, listing plants from which
seed can be obtained. On other occasions, persons interested in the Garden,
especially individuals who have seen it when visiting Georgetown, send seed of
plants that they think will be useful acquisitions. Further introductions are
made by keeping in touch with Botanic Gardens in other parts of the world
and especially with our neighbours.

In addition, when ordering seeds and bulbs of the commoner bedding
plants, annual and perennial, from commercial firms, new items are purchased
for trial from time to time. To obtain a large selection of seed is therefore
not difficult, but tnis only constitutes a small part of the problem. To begin
with, seed which takes a long time in transit may not germinate at all on
arrival, or only yield one or two plants; but if successful germination is
obtained, the plants are basketed and kept in the nursery until ready to put
out. The next problem is the selection of a suitable site. Apart from the fact
that, without overcrowding, it is now difficult to find a site for large trees or
palms in the Garden except where a gap is caused by a plant dying, or a stretch
of water for a new aquatic where it will not be crowded out, it is also often
necessary to try and find a ‘ high ’ spot for a new plant which may not be able
to stand ‘ wet feet.’ ‘ High ’ spots in a garden laid out on a totally flat area
of heavy clay soil, a few inches only above sea level, are naturally at a premium.
In addition the soil of the Garden is exceptionally heavy, and contains none of
the * caddy ’ found in some other parts of Georgetown. Many plants therefore
can make no headway under these conditions, and either die soon after planting
out, or are never as effective as they would be in a more congenial habitat.
Others on the other hand turn out unexpectedly well. It is therefore sometimes
difficult to choose the best place for a new introduction when its size and

RECENT INTRODUCTIONS OP ORNAMENTAL PLANTS IN THE BOTANIC GARDEN. 211

appearance at maturity are problematical. Finally, our rather uncertain
seasons of rainfall and very constant temperature are by no means well suited
to bring about the best floral display from plants suited to a climate where
there are marked and regular changes of season.

However, despite these difficulties, many new species are introduced to the
Garden; some to become permanent inhabitants, others lasting for shorter
periods, and the remainder of this note deals with some of the more striking
introductions made during the last few years.

Trees, and more especially flowering trees, naturally constitute some of the
most conspicuous features in the Garden, and our most attractive introduction
in recent years has been the pink-flowered Cassia nodosa , obtained from
Trinidad. It grows quickly in the Garden, is a beautiful sight when in flower
(from May onwards) and a well shaped tree with abundant foliage when not
blossoming. There is a plant near the North West corner and one by the No. 3
lake. Another rather striking introduction from the same source was the small
‘Orchid Flower' tree, Monad ora tenuifolia , of which a plant was established
a short way up the avenue, on the South side, after a previous introduction had
failed. Perhaps the most remarkable of all, when in full flower, is the Carib
wood, Sabima cannalis, obtained from Dominica, another small tree, which
during its short flowering period is covered in bright red blossoms. There is
a plant North of No. 2 lake and another on the avenue, but it is not very well
suited to our soil and several other plants have died. Two other small trees
with most beautiful blossom are Erythriua vancgata var. orientalis, with deep
scarlet flowers, which w r as obtained from a Georgetown garden, and Erythrina
sencgalevsis , w r ith flowers similar to the Oronoquo, which came from the Arnold
Arboretum, Cuba. Both are to be seen in the Flower Garden and blossom
during dry weather. Cordia sebestena t several shades of which w r ere obtained
from Barbados, is also to be seen in Regent Street. The flowers are jpretty,
but the tree does not blossom as profusely as it does in the drier West Indian
Islands. Markham ia Hildebrandtii , a yellow-f lowered tree recently introduced
from Kenya, promises well. Other small flowering trees that are new include
Glyricidia sepinm from Puerto Rico and some Bauhinias {acuminata Kurzii ,
foment osa and violacea ) from the United States Department of Agriculture.
New foliage trees that seem to be promising include Enterolobium cijclocai pum ,
Mcsua ferrea and Parkia Roxhurghii , all obtained from Ceylon, Acacia aurictd-
araeformis , sent us from the United States Department of Agriculture, and the
smaller Acacia spbaerocephala , obtained from Dominica.

The Georgetown Garden is well known for its collection of Palms, begun
at the outset by G. S. Jenman. Recent successful additions include Butin
eapitata <and B. yatai t Chamaerops humilis , Phoenix dactyl if era and Washing-
tonia robusta , obtained from Coconut Grove Palmetum, Florida, and Mr. David
Barry of California, Coleospadix onionensis , Geonoma gracilis and Roystonea
borinqnena from Trinidad and Euterpe stei'ophylla, Martinezia e^osa, M . Lin-
deniana and Korthalsia grandis from other sources. It is as yet too early to
"say whether a number of other recent palm introductions will become success-
fully established or not.

212

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 4.

Before turning to smaller plants, reference may also be made to the ‘Male*
bamboo. Dendrocalamus strictus , which has been re-introduced from Puerto
Rico and Florida, and is becoming well established.

Some of the most striking acquisitions nave been among flowering shrybs
and climbing plants. Cassia biflora , recently obtained from Barbados, is a
pretty little shrub, quick growing, on the stems of which are borne masses of
yellow flowers, and which blossoms for several months on end. It has proved
very suitable to local conditions and is somewhat reminiscent of Broom when
in flower. Calliandra Gnildingii , a quick-growing shrub, sometimes almost
attaining the size of a small tree, was sent from Trinidad. It is extremely
quick growing, bearing tufts of pink and white flowers, and there are now a
good many plants in the Garden, and in other parts of Georgetown. There is
one opposite the Garden entrance and another by the aviary. Trinidad has
also been a source of several other new shrubs. Two new Hibiscus varieties—
‘Sunset’ and another with copper-coloured leaves, have come from there; also
a white Poinsettia (which has made rather poor growth), the blue-flowered
Clerodewdron vgandewse, Mussaewda erythrophylla (another rather delicate
plant in the Garden) and the pink and white varieties of Barleria cristata.
Another Barleria (B. lavcifolia') , with yellowifeh-orange flowers, was obtained
from the Arnold Arboretum. Tinnea aethtopica sent from Jamaica is a re-
introduction. One of the ‘ Bottle Brushes Callistemon lanceolatus , from
Queensland, is new. Two small shrubs which have proved most successful as
border plants are Clerodendron fallax with large leaves and striking heads of
scarlet flowers, and Crossandra nwdulae folia , with orange red flowers, received
from Dominica. A new pale lilac shade of the King (Queen) of Flowers,
Lagerstroevda indica , was obtained from a Georgetown Garden.

Passing on to the climbing plants, some of the new Bougainvillaeas have
nerhaps proved the most attractive innovations, especially the variety * Helen
McLean’ from Trinidad and the very similar ‘Louis Wathen’ from Ceylon, with
‘flowers’ showing a range of shades from reddish-orange to rose pink; these with
another pink variety, ‘ Lady Wilson ’ from Trinidad, are all sub-varieties of
B> spectabiUs var. Rosa Catalina . A very deep tinted variety of the common
purple Bougainvillaea, growing on an arch by the Garden’s office, also came
from Trinidad. A number of striking and interesting Aristolochias were
obtained from the Arnold Arboretum, including argyroneura , elegans f ridicttla
and the enormous ' Duck Flower A . grandiflora, which has however a most
unpleasant odour of carrion, to attract flies. These, with A. ringens t from the
United States Department of Agriculture, are grown in and about the nursery
and rockery. Argyreia speciosa , known as the Cephalic Vine in the West
Indies, is a large leaved and vigorous climber, with purple flowers, growing
now on the vegetable garden fence. It was obtained from Jamaica and is most
suitable for hiding walls and palings. Several pretty Ipomoeas have been
introduced, including the white flowered semi-climbing Ipomoea arbore a t
received from Mexico, some pale blue varieties obtained from commercial firms,
a yellow species, Ipomoea pterodes , possibly indigenous, and a lilac-coloured
species sent us from Abyssinia. Unfortunately, some of these introduced

RECENT INTRODUCTIONS OF ORNAMENTAL PLANTS IN THE BOTANIC CARDEN* 213

Ipomoeas do not seed in the Garden and so are difficult to reproduce. Two
indigenous climbers, the Raieteur Vine, Bmisteria (?) ciliata and ‘black-eyed
Susan \ Thunbergia alata, of which there is both an orange-yellow and a white
form, have proved very useful. Cryptostegia grandiflora and Ruellia speciosa
both of which had formerly grown in the Garden and been lost have been
re-introduced, the former from Suddie and the latter from Georgetown.
Finally, a double flowered form of the Pink Coralita, obtained from Barbados,
is of interest, though not such a vigorous grower as the ordinary form.

In the beds of the Flower Garden and around the Nursery several new
varieties of bedding plants have appeared in the last few years, and most
conspicuous among these have been some new Cannas, the first suckers of which
came from Jamaica, and which have been gradually worked up so that now they
can be massed in beds and borders. The most successful of these newer
varieties have been the Salmon Pink 4 Sheherziade *, and the rather similar
4 Hungarin \ the cream white 4 Eureka the orange yellow and red varieties
4 Prince of Orange ’ and 4 Gyphaete \ and the Red ‘ Ambassador \ the latter
with purplish leaves. The scarlet ‘ President ’ has been in the Gardens for a
long time. A purple Salvia from Bermuda and the Barbados Lupin, Crotalaiia
zanzaharica , have also been most successful, and Strobihmthus isophyllus, with
purnlish-blue tunnel-shaped flowers, sent us from the Arnold Arboretum, has
found itself well adapted to local conditions and seeds readily. In addition,
new varieties of the common annuals and perennials are often obtained from
the recognised commercial seedsmen.

The shaded Rockery has received considerable attention of late, and in it
are a number of new plants. Btowallia spectosa , which grows splendidly
under light shade, was first introduced by Lady Northcote. A variety
of shades of Achimenr* were obtained from Messrs. Suttons, and
have been most satisfactory. Several indigenous Gesueriaceae , including
species of Episcia y Tussacia pulchella and another species of this genus, also
collected in the interior, add colour to the beds. From a collection of
Amaryllids received from Florida, so far Zephyranthes Ajax alone has
flowered several times, but some of the others may yet blossom. A large
yellow-flowered species of Zephyranthes from Barbados has also flowered
recently and a variety of Hippeastrum solandridovum from Bermuda. A plant
of the Jacobean Lily, Spreckelia formosissima, was acquired Ifom a local
garden, and one plant of the White Anthurium Lily has been obtained from
Trinidad. With difficulty one or two plants of a white Arum from Bermuda
have recently been coaxed into flower. #

In conclusion attention must be drawn to tw T o valuable new aquatic
introductions, namely Victoria cruziam , and Nelumbo luteum . Seeds of the
former, which is a native of the Amazon, were obtained from the New
York Botanic Garden, and the plant has been established in a small
trench immediately south-east of the 4 oval \ on the Avenue. The leaves and
flowers are similar to, but considerably smaller than those of V . regia .
Nelumbo luteum , the yellow Lotus Lily, is indigenous to Florida, but the

214 AGRICULTURAL JOURNAL OP BRITISH GUIANA. [X, 4.

seed was obtained from Jamaica, and after establishing one plant in a trench
running at right angles to the North of the North Serpentine Drive, near
No. 3 lake, the plant spread rapidly and in a few months had filled half of
the trench. This yellow lotus was introduced into the Garden many years
ago, but crossed with the Pink Lotus— N, nucifera. The pink lotus proved
dominant, and finally the yellow species was lost entirely' but not before
the pink had lost its pure deep shade, which was replaced by a paler colour,
varying in degree, the result of the cross, and which is now to be seen
in most of the lakes and trenches of the Park lands.

A few years ago the true pink was re-introduced from Berbice, and
is established in another trench, running off the North Serpentine Avenue,
near the Apiary.

CATALOGUE OF THE LEPIDOPTEHA RHOUALOOEllA
(BUTT EH FLIES) OF BKITISH G V I A X A — ( ( onduded).

ARTHUR HALL, F It. Km S

621. PAPILIO PAIJSAN1AS.

P. pausauias, Hewitson, Trans. Ent. Soc. 1852, p. 22, t. 6, f. 2.
Demerara River; Mt. Roraima. A very rare species and a good mimic of
Heliconius clytia and its allies.

522. P. ARIARAT1IES MENES.

P. ariarathes menes, Rothschild & Jordan, Nov. Zool. XIII, p. 672, t. 8.
f. 57 (1906).

Bartica; Berbice; Christianburg on the Demerara River; Kamakusa. One
of the rarer species.

523. Papilio protesilaus.

P. protesilaus, Linnaeus, Syst Nat. 1, p. 463, n. 29 (1758).

Demerara River. Sometimes common at certain times of the year but its
season seems to be short. Several specimens may sometimes be seen settling
together in patches on the banks of rivers, generally in company with a large
number of Catopsilias.

524. Papilio telesilaus.

P. telesilaus, Felder, Vrh. Zool. Bot. Ges. XIV, p. 301, n. 179, p. 345,
n. 90 (1864).

Demerara River; Essequibo River. Sometimes common in company with
the preceding species and of similar habits.

525. Papilio glaucolaus leu c as.

P. glaucolaus leucas, Rothschild & Jordan, Nov. Zool. XIII, p. 709,
t. 9, f. 65 (1906).

Demerara River; Berbice.

526. Papilio molops hetaerius.

P. molops hetaerius, Rothschild & Jordan, Nov. Zool. .XIII, p. 711,
t. 9, f. 61 (1906).

In the Tring Museum from Demerara.

216 AGRICULTURAL JOURNAL OP BRITISH GUIANA. tX 4.

527. PAPILIO AGESILAUS AUTOSILAUS.

p , a utosi1au8 f Bates, Trans. Ent. Soc. 1861, p. 348.

Essequibo River; Demerara River.

528. Papilio dolioaon.

P. dolioaon , Cramer, Pap. Ex. I, t. 17, C, D (1775).

Demerara River; Takutu; Mackenzie.

Family IIKSFFRIDAE.

Sub-family PYRRHOPYGINAE.

529. Pyrrhopyge garata.

P. garata, Hewitson, Trans. Ent. Soc. 1866, p. 483.

Demerara River; Omai.

530. Pyrrhopyge phidias.

Papilio phidias, Linnaeus, Syst. Nat. I, p. 485, n. 164 (1758).
Mabaruma. ,

531. Pyrrhopyge draudti.

P. draudti, Bell, Journ. N. York Ent. Soc. XXIX, p. 435 (1931).

In the British Museum from “ British Guiana ”.

532. Pyrrhopyge zeleucus.

Hespiria zeleucus, Fabricius, Ent. Syst. Ill, (1), p. 346, n. 317 (1793).
Demerara River; Kaieteur Falls.

533. Pyrrhopyge styx.

P. styx, Moschler, Verh. Zool. Bot. Ges. Wien XLVIII, p. 209. '
Friendship, Berbice; Mt. Roraima.

534. Pyrrhopyge amyclas.

Papilio amyclas, Cramer, Pap. Ex. Ill, t. 199, F C1792).

Georgetown ; Demerara River. Mr. L. D. Cleare informs me that the larva
of this species lives upon Guava.

535. Mysoria venezuelae.

M. venezuelae, Scudder, Rep. Peab. Acad. VI, p. 67 (1872).

Omai; Parika; Mt. Roraima.

536. AUENIS amra.

Pyrrhopyge amra, Hewitson, Ex. Butt. IV, Pyrrhopyge t. 8, f. 16, 17
(1871).

In the British Museum from “ British Guiana".

CATALOGUE OF THE LEPIDOPTERA RHOPALOCERA OF BRITISH GUIANA. 217

687. Yanguna tetricus.

Ymguna tetricus, Bell, "Entomologist” LXIV, p. 285 (1981).

The type, the only specimen known to me, came from Mt. Roraima.

Sub-family HESPERI1NAE.

538. Tarsoctenus papias.

Pyrrhopyga papias, Hewitson, Ex. Butt. II, Pyrrhopyga, t. 1, f. 4
(1857).

Carimang River.

589. Tarsoctenus rupibasis.

T. rufibasis, Mabille & Boull., Ann. Sci. Nat. Paris XVI, p. 24.
Demerara River; Omai.

640. EUDAMUS PROTEUS.

Papilio proteus, Linnaeus, Syst. Nat. I, p. 484, n. 163 (1758).

An abundant species everywhere.

641. Eudamus dorantes.

Papilio dorantes, Stoll, Suppl. Cram. t. 39, f. 9 (1790).

Generally distributed and common.

542. Eudamus eurycles.

Hesperia eurycles, Latreille, Ene. Meth. IX, p. 750, n. 5 (1823).
Generally common.

643. Eudamus simplicuis.

Papilio simplicuis, Stoll. Suppl. Cram. t. 39, f. 6, 6E (1790).

Another very common and generally distributed species.

644. Eudamus pilatus.

E. pilatus, Plots, Bull. Mosc. 1881, p. 2.

Georgetown; Demerara River.

545. Eudamus lindora.

, Goniurus lindora, Butler, Trans. Ent. Soc. 1870, p. 491.

In the British Museum from British Guiana.

546. Eudamus catillus.

Papilio catUhis, Cramer, Pap. Ex. Ill, t. 260, F, G. (1782).

Bartica; Omai.

218

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

CX, 4.

547. Eudamus asine.

E. asine, Hewitson, Descr. Heap. p. 5, n. 5 (1867).

Quonga.

548. Eudamus stylites.

E. stylites, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 63, n. 16 (1869).
Quonga.

549. Eudamus doryssus.

E. doryssus, Swainson, Zool. 111. Ins. II, t. 48, f. 2 (1933).
Demerara; Omai; Berbice; Quonga; Carimang River.

650. Eudamus albimargo.

Thymele albimargo, Mabille, Bull. Soc. Ent. Fr. (5), V, p. 213 (1876).
Bartica; Omai; Quonga; Carimang River; Takutu; Kaieteur Falls;
Mabaruma. Evidently widely distributed but generally found singly.

551. Eudamus virescens. (

E. virescens, Mabille, Bull. Soc. Ent. Fr. 1877, p. 39.

In the British Museum from “British Guiana.”

652. Eudamus orion.

Papilio orion, Cramer, Pap. Ex. II, t. 155, A, B (1779).

Demerara; Omai; Kaieteur Falls. A handsome and rather scarce species

553. Goniurus talus.

Papilio talus, Cramer, Pap. Ex. II, t. 176, D (1779).

Demerara; Takutu; Carimang River.

654. Goniurus coelus.

Papilio coelus, Cramer, Pap. Ex. IV, t. 243, C, D (1782).

Bartica; Carimang River.

555. PROTEIDES IDAS.

Papilio idas, Cramer, Pap. Ex. Ill, t. 260, A, B (1782).

Berbice; Friendship; Bartica.

556. Acolastus AMYNTAS.

Papilio amyntas, Fabricius, Syst. Ent. p. 583, n. 384 (1776).

Bartica; Omai.

557. Thymele fulgerator.

Papilio fulgerator, Walch, Naturf. VII, p. 115, t. 1, f. 2a, b (1775)
Generally distributed in forest regions but not very abundant.

CATALOGUE OP THE LEPIDOPTERA RHOPALOCERA OF BRITISH GUIANA. 219

558. THYMELE AULESTES.

Papilio aule8tes, Cramer, Pap. Ex. Ill, t. 283, E-G (1782).

Mt. Roraima.

659. Thymele enotrus.

Papilio enotrus, Cramer, Pap. Ex. IV, t. 364, G, H (1782).
Demerara; Essequibo River; Annai.

560. Thymele apastus.

Papilio apastus, Cramer, Pap. Ex. II, t. Ill, D, E (1779).

Single specimens from Bartica and “ British Guiana.”

561. Telegonus creteus.

Papilio creteus, Cramer, Pap. Ex. Ill, t. 284, C, D (1782).
Georgetown; Berbice; Carimang River; Mt. Roraima.

562. Telegonus parmenides.

Papilio parmenides, Cramer, Pap. Ex. IV, t. 364, E, F (1782).
Demerara River.

563. Telegonus alardus.

Papilio alardus, Stoll, Suppl. Cram. t. 39, f. 7, 7F (1790).

Bartica.

564. Telegonus anaphus.

Papilio anaphus, Cramer, Pap. Ex. II, t. 178, F (1779).

Generally distributed and common.

565. Telemiades amphion.

Proteides amphion, Hiibner, Zubr. Ex. Schmett. f 631, 632 (1832).
Carimang River; Kaieteur Falls.

566. Telemiades azines.

Eudamus azines, Hewitson, Descr. Hesp. p. 17, n. 31 (1867).
Demerara River; Carimang River.

567. Telemiades ceramina,

T. ceramina, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 69, n. 5
(1869).

In the British Museum from “ British Guiana ”.

568. Telemiades littera.

T. littera, Mabille, Petit. Nouv. Ent. 1877, n. 180.

Kaieteur Falls (A. Hall).

669. Cecropterus neis.

Cecrops neis, Hiibner, Zubr. Ex. Schmett. f 619, 620 (1832).

Berbice; Bartica; Carimang River.

670. Cecropterus itylus. *

Autochton itylus, Hiibner, Zubr. Ex. Schmett. f. 249, 250 (1823).
Parika; Bartica; Demerara.

230 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 4.

571. CECROPTERUS AUNUS.

Pwpilio aunus, Fabricius, Spec. Ins. II, p. 134, n. 618 (1781).

Widely distributed and abundant.

572. Ectomis adoxa.

P. adoxa, Mabille & Bull., Ann. Soc. Ent. Belg. 1878, p. 32.

Bartica. A very rare species otherwise only recorded from Cayenne.

573. Physalea pausias.

Eudamus pausias, Hewitson, Descr. Hesp. p. 17, n. 20 (1867).
Berbice; Carimang River.

574. Nascus caepio.

Telemiades caepio, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 68, n. 2
(1869).

Annai; Quonga; Carimang River.

575. Bungalotis salatis.

Papilio salatis, Cramer, Pap. Ex. IV, t. 393, E (1782).

Quonga.

576. Bungalotis midas.

Papilio midas, Cramer, Pap. Ex. I, t. 63, G (1779).

A pair of this fine species is in the British Museum from Demerara. Also
recorded from Mackenzie.

577. Bungalotis euribates.

Papilio euribates, Cramer, Pap. Ex. IV, t. 393, D (1782).

In the British Museum from “ British Guiana.”

678. COGiA CALCHAS.

Eudamus calchas, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 68, n.
22 (1869).

Bartica; Quonga.

579. Hydraenomia orcinus.

Eudamus orcirms, Felder, Reise Nov. Lep. Ill, p. 510, t. 71, f. 4, 5
(1867).

A male from “ British Guiana ” in the British Museum.

*580. Paradros phoenice.

Eudamus phoenice, Hewitson, Descr, Hesp. p. 19, n. 36 (1867).
Demerara; Carimang River.

CATALOGUE OP THE LEPIDOPTERA EHOPALOCERA OF BRITISH GUIANA. 221

581. PARADROS EOUS.

Eudanms eous, Hewitson, Descr. Heap. p. 20, n. 87 (1867).

Carimang River.

582. Lignyostola crinisus.

Papilio crinisus, Cramer, Pap. Ex. IV, t. 300, G, H (1782).

Berblce; Demerara River; Omai; Akyma.

583. HYALOTHYRUS NELEUS.

Papilio neleus, Linnaeus, Syst. Nat. I, p. 488, n. 187 (1758).

Omai.

584. Hyalothyrus nitocris.

Papilio nitocris, Cramer, Pap. Ex. IV, t. 293. F, G (1782).
Demerara; Omai.

585. Mionectes infernalis.

Enthevs infernalis, Mdschler, Verh. z. b. Wien. XXVI, p. 329, t. 4,
f. 21 (1876).

Demerara; Omai; Kaieteur Falls.

586. Marela tamyroides.

Eudamus tamyroides, Felder, Reise Nov. Lep. Ill, p. 509, n. 886,
t. 70, f. 13, 14 (1867).

Demerara; Carimang River.

587. Phanus vitreus.

Papilio vitreus, Cramer, Pap. Ex. IV, t. 365, D (1782).

Bartica; Omai; Carimang River; Kaieteur Falls.

588. Phanus marshalli.

P. marshalli, Kirby, Proc. Roy. Soc. Dublin, 1880, p. 339.

Bartica. Doubtfully distinct from the preceding.

589. Entheus priassus.

' Papilio priassus, Linnaeus, Syst. Nat. I, p. 487, n. 185 (1758).
Quonga; Carimang River.

590. Entheus gentius.

Papilio gentius, Cramer, Pap. Ex. II, t. 179, C (1779).

Georgetown; Omai; Annai; Carimang River. A fairly common species.

222

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

rx, 4.

591. Entheus eumelus.

Papilio eumelus, Cramer, Pap. Ex. II, t. 156, E (1779).

Carimang River.

592. Grynopsis coeleste.

Phareas coeleste, Westwood, Gen. Diurn. Lep. t. 78, f. 4 (1852).

This fine and rare species is in the British Museum from the Carimang
River and Mt. Roraima.

693. Celaenorrhinus eligius.

Papilio eligius, Cramer, Pap. Ex. IV, t. 354, H (1782).

Quonga.

594. Celaenorrhinus astrigera.

C. astrigera, Butler, Trans. Ent. Soc. 1877, p. 153.

Quonga.

595. Pythonides menedemus.

P. menedemus, Godman & Salvin, Biol. Cent. 4m. Rhop. p. 362. 1. 32
f. 17, 18 (1894).

Demerara; Carimang River.

696. Pythonides cerialis.

Papilio cerialis, Cramer, Pap. Ex. IV, t. 392, n, o (1782).

Generally distributed and common.

597. Pythonides assecla.

P. assecla, Mabille, Bull. Soc. Ent. Belg. 1883, p. 76.

Mabaruma. (A. Hall). Marlissa in Berbice.

598. Pythonides lucullea hew.

Leucochitouea lucullea, Hewitson, Descr. Heap. p. 46, n. 1 (1868).
Demerara; Carimang River; Kaieteur Falls.

599. Pythonides contubernalis.

P. contubernalis, Mabille, Bull. Soc. Ent. Belg. 1883, p. 76.

Kaieteur Falls (A. Hall).

600. Ate lagia.

Leucochitouea lagia, Hewitson, Descr. Heap. p. 47, n. 3 (1868).
Kaieteur Falls (A. Hall). There are also specimens from “British
Guiapia " in the British Museum.

CATALOGUE OF THE LEPIDOPTERA RHOPALOCERA OF BRITISH GUIANA. 228

601. Ate jovianus.

Papilio jovianus, Cramer, Pap. Ex. IV, t. 392, L, M (1782).
Demerara River; Bartica; Carimang River; Kaieteur Falls; Mabaruma.
Usually only found singly.

602. Spioniades artemides.

Papilio artemides, Cramer, Pap. Ex. IV, t. 391, L, M (1782).
Demerara; Mabaruma.

603. Pellicia tiphys.

P. tiphys, Godman & Salvin, Biol. Cent. Am. Rhop. II, p. 368, t. 83,
f. 6-10 (1894).

Generally common.

604. Pellicia didia.

P. didia, Moschler, Verh. z. b. Wien. XXVI, p. 341, t. 4. f. 25 (1876).
Parika; Mabaruma.

605. Pellicia macareus.

P. macaiius, Herrich-Schaeffer, Corresp. Blatt Regensb. 1870, p. 160.
Omai; Quonga: Carimang River.

*606. Pyrdalus corbulo.

Papilio corbulo, Cramer. Pap. Ex. IV, t. 354, A (,1782).

Carimang River.

607. Nisoniades hero.

N. hero, Evans, in lift.

Described from the Carimang River.

608.. Cyclosaemia anastomosis.

C. anastomosis, Mabille, Petit. Nouv. Ent. 1878, p. 230.

Carimang River.

609. Cyclosaemia carima.

C. carima, Evans, in lift.

Carimang River.

610. Cyclosaemia herennius.

Papilio herennius, Stoll, in Cramer, Pap. Ex IV, t. 392, E, F (1782).
Demerara River; Marlissa in Berbice.

611. Anastrus obscurus.

A. obscurus, Hiibner, Samml. Ex. Schmett. (1816-1841).

Demerara; Carimang River.

224 AGRICULTURAL JOURNAL Of BRITISH GUIANA. [X, 4.

612. Echelatus ROBIGUS.

E. robigus, Plots, Ex. Schmett. 20, t. 1006.

Quonga.

613. Echelatus sempiternus.

Achlyodes sempiternus, Butler & Druce, Cist. Ent. I, p. 114 (1872).
Bartica.

614. Eudamidas melander.

Pa/pilio melander, Cramer, Pap. Ex. Ill, t. 270, H (1782).

Carimang River.

616. Xenophanes tryxus.

Papilio tryxus, Cramer, Pap. Ex. IV, t. 334, G, H (1782).

Rather common and generally distributed.

616. Achylodes fridericus.

A. fridericus, Hubner, Zubr. Ex. Sehfnett. f. 611, 612 (1832).
Generally common.

617. Achylodes thiena.

A. thiena, Plotz, Exot. Schmett. 20, Hesp. t. 957.

Mentioned from British Guiana by Seitz. It is a very obscure species and
likely to be overlooked.

618. Antigonus nearchus.

Hesperia nearchus, Latreille, Humb. Bonpl. Obs. Zool. II, p. 135, t. 48,
f. 3. 4 (1811-1823).

Bartica. Not common.

619. Milanion hemes. *

Papilio hemes, Cramer, Pap. Ex. II, t. 103, F (1779).

Annai; Berbice; Carimang River; Kaieteur Falls.

620. Sebaldia busirus.

Papilio busirus, Cramer, Pap. Ex. Ill, t. 261, A-C (1782).

Marudi Mtn. Rupununi District (L. J. H. Ashburner).

621. Eantis thraso.

Urbanus vetus thraso, Hiibner, Samml. Ex. Schmett. (1806-16).
Bartica; Omai; Quonga.

622. Timochares trifasciata.

Leucochitonea trifasciata, Hewitson, Descr. Hesp. p. 49, n. 10 (1868).
- Carimang River.

CATALOGUE OB' THE LEPIDOPTERA RHOPALOCERA OP BRITISH GUIANA. 225

628. Elrietas ECLIFTICA.

Achlyodes eeliptica, Butler, Trans. Ent. Soc. 1877, p. 114.

Carimang River.

624. Diphoridas phalaenoidhs.

Urbanus vetus phalaenoides, Htibner, Samml. Ex. Schmett. (1806-16'.
A common species in most places.

626. Camtopleura ebenus.

C. ebenus, Mabille, Compt. Rend. Soc. Ent. Belg. 1883, p. 14.
Carimang River.

626. Cyclogypha thrasybulus.

Hesperia thrasibidus, Fabricius, Ent. Syst. Ill, (1), p. 346 (1793)
Omai; Mt. Roraima.

627. Cyclogypha tisia-s.

C. tisias, Godman & Salvin, Biol. Cent. Am. Rhop. II, p. 423, t. 88,
f. 16 (1896).

Mt. Roraima.

628. Gorgythion pyralina.

Helios pyralina, MOschler, Verh. Zool. Bot. Ges. Wien XXVI, p. 343,
t. 4, f. 31 (1876).

Widely distributed and very common.

629. PARAMIMA3 SCURRA.

Urbanus juvenis scurra, Hiibner, Samml. Ex. Schmett. (1806-1816).
Demerara River; Carimang River; Bartica; Kaieteur Falls.

630. CHARIDIA LUCARIA.

Leucochitonea htcaria, Hewitson, Descr. Hesp. p. 60, n. 12 (1868).

631. Chiomara mithrax.

C. mithrax, Moschler, Verh. Zool. Bot. Gcs. Wien, 1878, p. 226.
Demerara River; Bartica.

632. Chiomara punctum.

C. punctum, Mabille, Petit. Nouv. Ent. 1888, p. 229.
tn the British Museum from the Demerara River.

633. Chiomara asychis.

Papilio asychis, Cramer, Pap. Ex. IV, t. 334, E, F (1782).

There are specimens in the British Museum labelled “ Kingston, Demerara,’’
Possibly Georgetown Js meant. It is a common West Indian species,

226

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[X, 4.

634. Hesperia syricthus.

Papilio syricthus, Fabricius, Syst. Ent. p. 634, n. 894 (1776).

One of the commonest of all butterflies; abundant both in forest and in
cultivated places.

636. Helioptes arsalte.

Papilio arsalte, Linnaeus, Syst. Nat. I, p. 469, n. 67 (1758).

Widely distributed and common, usually in open or cultivated places.

636. Helioptes petrus.

Brontiades petrus, Hiibner, Verz. Bek. Schmett. p. 113 (1816).
Georgetown; Parika; Bartica; Takutu. Less abundant than H. arsalte.

Sub-family PAMPHILINAE.

637. Hylephila phylaeus.

Papilio phylaeus, Drurg, 111. Ex. Ent. I t. 13, f. 4, 5 (1773).
Generally distributed and common.

638. Thymelicus vibex.

T. vibex, Hiibner, Zubr. Ex. Schmett. f. 685, 686 (1832).

Widely distributed and sometimes common.

639. THYMELICUS athenion.

Talides athenion, Hiibner, Samml. Ex. Schmett. (1816-1841).

Another very common species.

640. Apaustus gracilis.

Ancyloxypha gracilis, Felder, Reise Nov. Lep. Ill, p. 520, t. 74, f. 28
(1867).

Bartica.

641. Ayrytone eulocius.

A. eidogius, Plotz, Exot. Schmett. 20, Hesp. p. 608.

Georgetown; Kaieteur Falls.

642. Atrytone gladolis.

A. gladolis, Dyar, Insec. Ins. Menstr. II, p. 5 (1914).

Bred by H. W. B. Moore, at Non Pareil Plantation from larva feeding on
the shoots of sugar cane.

643. Atrytone heberia.

A. heberia, Dyar, Insec. Ins. Menstr. II, p. 5 (1914).

Also bred by H. W. B. Moore at Non Pareil Plantation, the larva likewise
feeding upon sugar cane. Neither species is known to me in nature.

CATALOGUE OF THE LEPIDOPTERA RHOPALOCERA OF BRITISH GUIANA. 227

644. ZAR1ASPES MYS.

Urbanus vigorvs mye, Hiibner, Samml. Ex. Schmett. (1806-1816).
Demerara; Parika; Mabaruma; Mt. Roraima. Like other small species
probably common if looked for.

645. Zarhspes ferrago.

Z. ferrago, Plotz, Stett, Ent. Zeit. 1884, p. 163.

In the British Museum from Takutu (Whitely). Seitz gives this name as
synonym to Padraona e pictet us but the specimen in the British Museum is
certainly different.

646. Padraona epictetus.

Papilio epictetus, Fabricius, Ent. Syst. Ill, (1), p. 330, n. 252 (1793).
Demerara: Bartiea; Parika; Carimang River. A common species.

647. Padraona tryhana.

P. tryhana, Kaye, Trans. Ent. Soc. 1914, p. 581, t. 30, f. 3.

Bartiea; Demerara; Essequibo River.

648. Trjoedusa milvius.

• T. milvius, Mabille, Gen. Ins. 17d, p. 145.

Takutu.

049. PRENES NYCTELIUS.

Hesperia nyetclius, Latreille, Enc. M<"th. IX, p. 716 (1823).

Demerara; Berbice.

650. Prenes sylvicola.

Gov turns sylvicola, Herrich-Schaeflfer, Corresp. Blatt. Regensb. XIX,
p. 55, n. 13 (1865).

Generally distributed and abundant in cane fields.

651. Prenes ocola.

P. ocola, Edwards, Proc. Ent. Soc. Phil. II, p. 20, t. 11, f. 4 (1863).
Berbice; Quonga; Mt. Roraima.

652. Prenes quonga.

P. quonga, Evans, in litt.

Type from Quonga in the British Museum.

653. Prenes evadnes.

Papilio evadnes. Cramer, Pap. Ex. IV, t. 343, G, H (1782).

Demerara; Quonga; Takutu; Kaieteur Falls,

[X, 4.

228' AGRICULTURAL JOURNAL OF BRITISH GUIANA.

654. PRENES NERO.

Hesperia nero, Fabricius, Ent. Syst Suppl. p. 488 (1798).

Quonga; Mt. Roraima.

655. Paraides brino.

Papilio brino, Cramer, Pap. Ex. IV, t. 358, E, P; t. 292, C, D (1782).
In the British Museum from “ British Guiana.”

656. XENIADES ORCHAMUS.

Papilio orchamvs, Cramer, Pap. Ex. II, t. 155, E, F (1779).

Annai; Mt. Roraima.

657. XENIADES CHALESTRA.

Hesperia chalestra, Hewitson, Trans. Ent. Soc. 1866, p. 488.

Demerara River; Berbice.

658. Telles arcalaus.

Papilio arcalavs, Cramer, Pap. Ex. IV, t. 391, I, K (1782).

A male from “ British Guiana” in the British Museum.

659. Thespieus dalmani.

Hesperia dalmani, Latreille, Enc. Moth. IX, p. 747, n. 48 (1828). •
Omai.

660. Vacerra litana.

Hesperia litana, Hewitson, Trans. Ent. Soc. 1866, p. 494.

Quonga.

661. Niconiades xanthaphes.

Nisoniades xanthaphes, Htibner, Samml. Exot. Schmett. (1816-1841).
Georgetown; Berbice; Kaieteur Falls.

662. Niconiades caeso.

N. caeso, Mabille, Compt. Rend. Soc. Ent. Belg. 1891, p. 88.

Kaieteur Falls; Mackenzie.

663. PHEMIADES PROPERTIUS.

Hesperia propertius, Fabricius, Ent. Syst. Ill, (1), p. 325, n. 234
(1798). •

Demerara; Bartica; Carimang River.

664. RHINTHON CTNBA.

Hesperia cyma, Hewitson, Ann. Mag. Nat. Hist (4), XVIII, p. 456
(1876),

Jfortica,

CATALOGUE OB’ THE LEP1DOPTERA RHOPALOCEEA OP BRITISH GUIANA. 229

666. Bhinthon bistrigula.

Cobalus bistrigula, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 83.
n. 64 (1869).

Quonga.

666. RHINTHON ALUS.

Rhinthon alus, Godman & Salvin, Biol. Cent. Am. Rhop. II, p. 632
t. 98, f. 4-6 (1900).

Parika (A. Hall).

667. Rhinthon erebina.

R. erebina, Moschler, Verh. Zool. Bot. Ges. Wien 1878, p. 211.

Kaieteur Falls.

668. Rhinthon melius.

Thracides melius, Hiibner, Zubr. Ex. Schmett. f. 765, 766 (1832).

Quonga.

669. Rhinthon megalops.

R. megalops, Godman & Salvin, Biol. Cent. Am. Rhop. II, p. 533, t. 88,
f. 11-13 (1900).

Parika.

670. Rhinthon anthracinus.

R. anthracinus, Mabille. Petit. Nov. Ent. 1877, p. 162.

Quonga.

671. Cobalus virbius.

Papilio virbius, Cramer, Pap. Ex. It, t. 143, G (1779).

Demerara; Carimang River.

672. Cobalus argus.

C. arguK, Moschler, Verh. Zool. Bot. Ges. Wien. 1878, p. 212 (1878''.
Bartica.

673. CobalUs aethra.

C. aethra, Plotz, Exot. Schmett. Heap. 20, t. 1399.

Bartica.

671. .Cobalus cannae.

C. cannae, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 83 (1869).

In the British Museum from “British Guiana.’*

676. COBALOPSIS DYSCRlTUS.

C. dyscritus, Mabille, Compt. Rend. Soc. Ent. Belg. 1891, p. 95.
Carimang River; Takutu.

[X, 4.

23Q AGRICULTURAL JOURNAL OP BRITISH GUIANA.

676. Onophas COLUMBARIA.

Pamphila columbaria, Ilerrich-Sehaeffer, Corresp. Blatt. Regensb.
p. 169 (1870).

Carimang River.

677. PERIMELES REMUS.

Hesperia tanus, Fabricius, Ent. Syst. Supp. p. 434 (1798).

Mt. Roraima.

678. Eutychide cingulicornis.

Cobalus cingulicornis, Herrieh-Schaeffer, Prodr. Syst. Lep. p. 82,
n. 52 (1869).

Bartica; Quonga; Carimang River; Mt. Roraima. This species seems to
be strangely local. 1 once took four or five specimens off *he same Euphorbia
bush at Bartica but never saw one anywhere else.

679. Eutychide subcordata.

Cobalus subcordata, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 82,
. n. 60 (1869). '

Caripiang River; Mt. Roraima.

680. Eutychide asema.

E. asema, Mabille, Compt. Rend. Soc. Fnt. Belg. 1891, p. 171.
Takutu.

681. Cobalopsis edda.

Pamphila edda, Mabille, Compt. Rend Soc. Ent. Belg. 1891, p. 170.
Takutu.

682. Phanis justinianus.

Hespena justinianus, Latreille, Enc. Moth. IX, p. 760 (1823).

Quonga.

683. Phanis rezia.

P. rezia, Plotz, Exot. Schmett. 20, TIcsp. p. 466.

Bartica. The specimens do not seem to be typical and may belong to a
different species.

684. Phanis almoda.

Hesperia almoda, Hewitson, Trans. Ent. Soc. 1866, p. 499.

Quonga.

685. PHLEBODES TIBERIUS.

Apavstvs tiberius, Moschler, Verh. Zool. Bot. Ges. Wien 1882, p. 329.
Bartica.

CATALOGUE OP THE LEPIDOPTEBA RHOPALOCERA OP BRITISH GUIANA. 231

686. PHILEBODES RETICULATA.

P. reticulata, Plotz, Ex. Schmett. 20, Heap. t. 650.

Quonga; Carimang River; Mt. Roraima.

687. Lerema parumpunctata. ’

Goui-urus •parumpunctata, Herrich-Schaeffer, Prodr. Syst. Lep. Ill,
p. 76, n. 51 (1869).

Berbice.

688. Lerema mooreana.

L. mooieanu, Dyar, Inaec. Ins. Menstr. II, p. 4 (19141.

Bred at Georgetown by H. W. B. Moore from larva feeding on the shoots
of sugar cane. (Dyar).

689. PAPIAS INTEGRA.

Pamphilia Integra, Mabille, Compt. Rend. Soc. Ent. Belg. 1891, p. 169.
Carimang River.

690. Papias diotys.

P. dicti/s, Godman & Salvin, Biol. Cent. Am. Rhop. II, p. 560 t. 100,
f. 12, 13 (1900).

Mabaruma.

691. Papias leucopogon.

P. leucopogon, Piotz, Exot. Schmett. 20, Uesp. t. 287.

Mabaruma.

692. Tiiargella fuliginosa.

T. fuliginosa, Godman & Salvin, Biol. Cent. Am. Rhop. II, p. 565,
t. 100, f. 24, 25 (1900).

Parika; Kaicteur Falls. Locally common.

693. Mnasitheus simplicissimus.

Pamphila simplicissimus, Herrich-Schaeffer, Corresp. Blatt Regensb.
1870, p. 159.

Bartica.

694. Mnasatcas uniformis.

. Pamphila uniformis, Butler & Druce, Cist. Ent. I, p. 113 (1872).
Georgetown.

695. Vehilius illudens.

Cobalus illudens, Mabille, Compt. Rend. Soc. Ent. Belg, 1891, p. 73.

In the British Museum from “ British Guiana.”

232 AGtuetftftjftAl journal of RMtiSh GVU.uk. tX 4.

696. Vehiuus stictomenes.

Staphylus stictomenes, Butler, Trans. Ent. Soc. 1877, p. 163.

New Amsterdam; Demerara; Taltutu; Mabaruma.

697. Megistias tripunctatus.

Hesperia tripunctata, Latreille, Enc. Meth. IX, p. 762, n. 62 (1823).
Demerara; Bartica.

698. Megistias leucone.

M. leucone, Godman & Salvin, Biol. Cent. Am. Rhop. II., p. 576, t, 101.
1 19-21 (1900).

Omai; Takutu.

699. Parphobus storax.

Phlebodes storax, Mabille, Compt. Rend. Soc. Ent. Belg. 1891, p, 83.
Mt. Roraima.

700. VORATES DECORA. '

• Cobalus decora, Herrich-Schaeffer, Prodr. Syst, Lep. Ill, p. 81.

Takutu ; Mabaruma.

701. Molo mango.

Hesperia mango, Gu&i6e, Vinson’s Voy. Mad. Lep. p. 40 (1865).

In the British Museum from Demerara. This species is better known
under the name of Af. heraea Hew., owing to the fact that the locality of
Gu6n6e’s Hesperia mango was erroneously given as Madagascar!

702. Paracarystus hypargyra.

Cobalus hypargyra, Herrich-Schaeffer, Prodr. Syst. Lep. p. 81, (1869).
Georgetown; Demerara River.

703. Paracarystus menetriesii.

Hesperia menetries, Latreille, Enc. Meth. IX, p. 760, n. 91 (1823).
Demerara; Carimang River.

704. Carystus PHORBUS.

Papilio phoreus, Cramer, Pap. Ex. II, t 156, D (1779).

Several specimens from “ British Guiana ” in the British Museum.

705. Carystus artona.

Hesperia artona, Hewitson, Descr. Heap. p. 27 (1868).

Widely distributed and very common.

706. Carystus jolus.

Papilio jolus, Cramer, Pap. Ex. IV, t. 292, I, K (1782).

Parika (A. Hall).

catalogue of The lepidoptera bhopalocEra of bbitish guiaNa.

707. ZENIS MINOS.

Hesperia mines, Latreille, Enc. Meth. IX, p. 756, n. 76 (1823).

Takutu.

708. ZENIS CALVIN A.

Hesperia calvina, Hewitson, Trans. Ent. Soc. 1866, p. 492.

Quonga; Kaieteur Falls.

709. Vettius phyllus.

Papilio phyllus, Cramer, Pap. Ex. II, t. 176, B, C (1779).

Demerara; Potaro River; Mabaruma.

710. Vettius laubea.

Hesperia laurea, Hewitson, Descr. Hesp. p. 28, n. 18.

Kaieteur Falls. This species seems doubtfully distinct from V. phyllm but
Seitz’s figure, with which my Kaieteur specimens agree, is rather different to
that of Hewitson and may represent something else.

711. Vettius lafresnayi.

Hesperia lafrenaye, Latreille, Enc. Meth. IX, p. 753 (1923).

Bartica; Carimang River; Kaieteur Falls.

712. COELIADES DUBIUS.

Papilio dubivs, Cramer, Pap. Ex. IV, t. 354, B, C (1782).

Demerara; Berbice.

713. Dion prinosa.

D. prinosa, Plotz, Exot. Schmett. 20, Hesp. t. 293.

Takutu.

714. Flacilla aecas.

Papilio aecas, Cramer, Pap. Ex. IV, t. 243, A, B (1782).

Bartica; Carimang River; Takutu; Mt. Roraima.

716. CYMAENES PERICLES.

Pamphila pericles, Moschler, Verh. Zool. Bot. Ges. Wien, 1878, p. 218.
Quonga.

716. CYMAENES TBLATA.

Cobalus telata, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 81, n. 43
( 1869 ).

Quonga.

717. Methionopsis ina.

M. ina, Pldtz, Exot. Schmett. 20, Hesp. t. 261.

Bartica; Carimang River; Kaieteur Falls.

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[X, 4.

718. Epeus veleda.

E. veleda, Godman & Salvin, Biol. Cent. Am. Rhop. II., p. 601, t. 108,
f. 21-23 (1901).

Kaieteur Falls.

719 . Epeus edata.

E. edata, Flotz, Exot. Schmett. 20, Heap. t. 580.

Quonga.

720. Callimormus filata.

Apaustus filata, Plotz, Stetl. Ent. Zeit. 1884, p. 158.

Abundant in nearly all localities. Common in the Botanical Gardens at
Georgetown.

721. Callimormus juventus.

C. juventus, Scudder, Rep. Peab. Ac. Sci. 1872, p. 74.

Quonga.

722. Callimormus corades.

<• Ancyloxypha corades, Felder, Verh. Zool.' Bot. Ges. Wien, 1862, p. 477.
Bartiea.

723. Mnestheus ludens.

Cobalus ludens, Mabille, Compt. Rend. Soc. Ent. Belg. 1891, p. 83.
Kaieteur Falls.

724. Artines atizies.

A. atizies, Godman & Salvin, Biol. Cent. Am. Rhop. II., p. 608, t. 103,
f. 49, 50 (1901).

Quonga; Mt. Roraima.

725. Carystoides sicania.

Hesperia sicania, Hewitson, Ann. Mag. Nat. Hist. (4), XVIII, p. 451
(1876).

Quonga.

726. Carystoides cathaea.

Hesperia cathaea, Hewitson, Trans. Ent. Soc. I860, p. 492.

Demerara River; Berbice; Carimang River.

727. Damas clavus.

Hesperia clavus, Erichson, Schomb. Reise III, p. 601 (1848).

Berbice.

* 728. ORSES CYNISCA.

Hesperia cynisca, Swainson, Zool. 111. 1, t. 40 (1820-1821)

Bartiea; Annai; Carimang River.

* CATALOGUE OP THE LEpiDQPTERA RHOPALOCERA OF BRITISH GUIANA. 235

729. Thracides PHIDON.

JPwpilio phidon, Cramer, Pap. Ex. Ill, t. 245, F, G (1782).

Demerara; Berbice. '

730. Thracides salius.

Papilio salius, Cramer, Pap. Ex. I, t. 68, E (1779).

Parika.

731. Thracides longirostris.

Papilio longirostris. Sepp, Surin. Vlind. I, t. 27 (1848).

Demerara; Berbice; Ida Sabina; Omai; Takulu; Quonga; Georgetown;
Bartica. A rather common species.

732. Thracides aroma.

Hesperia aroma, Hewitson, Descr. Ilesp. p. 24 (1867).

In the British Museum from “ British Guiana.”

733. Thracides chiomara.

Hesperia chiomara, Hewitson, Ex. Butt. IV, Hesperia, t. 2, f. 19
(1867).

Demerara River; Bartica; Carimang River.

734. Thracides fischeri.

Hesperia fischeri, Latreille, Enc. Moth. IX, p. 747, n. 50 (1823),
Carimang River; Kaieteur Falls.

735. Thracides decinea.

Hesperia decinea, Hewitson, Ann. Mag. Nat. Hist. (4), XVIII,
p. 452 (1876).

Kaieteur Falls.

736. Talides sergestus.

Papilio sergestus, Cramer, Pap. Ex. I, t. 74, C (1779).

Demerara; Quonga; Carimang River.

737. Talides adjunctus.

T. adjunctus, Plotz, Exot. Schmett. 20, Heap. t. 340.

Bartica.

738. Perichares coridon.

, Papilio coridon, Fabricius, Syst. Ent. p. 533, n. 385 (1775).

Demerara; Bartica; Quonga; Takutu: Mt. Itoraima.

739. Pyrrhopygopsis thrasea.

Hesperia thrasea, Hewitson, Trans. Ent. Soc 1866, p. 485.

A female from “ British Guiana ” in the British Museum,

536 AGRICULTURAL JOURNAL OP BRITISH GUIANA. tX 4.

740. Pyrrhopygopsis cleanthes.

Hesperia cleanthes, Latreille, Enc. Meth. IX. p. 732, n. 9 (1828).
Demerara.

ADDENDA.

Family JSATYRIDAE.

741. Euptychia mollina.

E. mollina, HUbner, Zutr. Ex. Schmett. f. 106, 106 (1818) .
Oronoque-New River confluence (G. A. Hudson).

742. Euptychia jesia.

E. Jesia, Butler, Lep. Ex. t. 4, f. 6 (1869).

New River (J. G. Myers) ; Upper Corentyne (G. A. Hudson).

743. Euptychia nebulosa.

E. nebulosa. Butler, Proc. Zool. Soc. 1866, p. 479, n. 61.

Parika (A. Hall).

744. Euptychia antonoe.

Papilio antonoe, Cramer, Pap. Ex. I, t. 60, E. F. (1779).

Parika (A. Hall).

746. Euptychia newtoni.

E. neirtovi, sp. nov.

Description. Male. Differs from E. libye L. in the L . - '.'ice of a round
whitish postdiscal spot on the fore wings just above vein 3. The female only
differs in the slightly lighter and more greyish colour of the under surface.
Types from Parika.

This species has hitherto been taken to be an individual form of E. libye
but Captain Riley has examined the genitalia and found them to be quite
distinct.

E. Newtoni also occurs in Trinidad and is in the British Museum
from the Lower Amazon; E. libye ranges throughout Tropical America.

746. Euptychia gera, hew.

E. gera, Hewitson, Ann. Mag. Nat. Hist. (2), VI, p. 439 (1860).
Oronoque-New River confluence (G. A. Hudson, Aug. 1937).

747. Euptychia briscius.

Satyru8 briscius, Godart, Enc. Meth. IX, p. 490, n. 42 (1828).

Annai; Barima River (C. E. Buckle).

748. Euptychia aegrota.

E. aegrota, Butler, Proc. Zool. Soc. 1866, p. 482, n. 72.

In the British Museum from Bartica.

CATALOGUE OF THE LEP1DOPTEBA RHOPALOCERA OF BRITISH GUIANA. 237

749. Euptychia CAERULEA.

E. caerulea, Butler, Lep. Ex. I t. 3, f. 1, 2 (1869).

Annai; Quonga; Bartica; Mt. Roraima.

760. Euptychia clorimbne.

Pwpilio clorimem, Stoll. Suppl. Cram. t. 13, f. 2, 2b, (1790),

Bartica (Coll. B.M.).

751. Euptychia furina.

E. furina, Hewitson, Ex. Butt. Ill, Euptychia t. 1, f. 4 (1862),
Quonga; Mt. Roraima; Oronoque-New River confluence. The British
Guiana specimens are not quite typical and probably represent a new sub-
species.

752. Euptychia itonis,

E. itonis, Hewitson, Ex. Butt. III. Euptychia t. 1, f. 3 (1862).

Annai; Takutu.

Family BRASSOLIDaE.

753. Selenophanes cassiope.

Papilio cassiope, Cramer, Pap. Ex. I, t. 57, A. B. (1779).

Konawaru on the Potaro (Coll. Ent. Div.) ; Mackenzie (Beccari Exp.).

Family NYMPHALIDAE.

Sub-family HELICONIINAE,

764. Heliconius salvinii.

H. salvinii, Dewitz. Mitt. Milnchen. Ent. Ver. I, p. 86.

Tumatumari (G. A. Bodkin) ; Matope; Cuyuni River (Coll. B. M.).

755. Heliconius clysonymus.

H. clysonymus, Latreille in Humb. Bonpl. Obs. Zool. II, p. 128, t. 42,
f. 1, 2, (1811-1819).

Issororo, N.W. District (L. D. Cleare).

Sub-family NYMPH ALIN AE.

756. EUNICA EUROTA.'

Papilio eurota, Cramer, Pap. Fix. I, t. 24, C.D. (1775).

Mazaruni River (C. B. Williams). (Coll. Ent. Div.).

757. Eunica SYDONIA.

Nymphalis sydonia, Godart, Enc. Moth. IX, p. 416, n. 207 (1923).
Essequibo River (Coll. Ent. Div.).

758. ' CATONEPHELB ANTINOE.

Nymphalia mtinoe, Godart, Enc. Meth. IX, p. 410, n. 197 (1823).
Catonephele beccarii, Verity, Mem. Soc. Ent. Ital. 1934, p. 77.
Marlissa, Berbice River (Beccari Exped.).

Seitz has figured a male of C. chromis under the name of C. antinoe and
this has misled Dr. Verity into re-describing the true C, antinoe as C. beccarii,

238 AGRICULTURAL JOURNAL OF BRITISH GUIANA. [X, 4.

759. CATAGRAMMA EXCELSIOR.

C. excelsior, Hewitson, Ex. Butt. II, Cato gramma t 7, f. 49, 50 (1858).
Verity records a female as having been taken on the Detnerara River by
the Beccari Expedition. If no mistake in identification has been made the.
record is a remarkable one as this very conspicuous species has not hitherto
been known from any locality nearer than the Rio Manes on the South side of
the Amazon.

760. Ectima LIBIA.

Papilio liria, Fabricius, Ent. Syst. Ill, (i), p. 239, n. 747, (1793).
Wismar (A. Hall, March 1939).

761. Megalura egina.

Timetes egina, Bates, Journ. Ent. II, p. 329, t. 10, f. 1 (1865).
“Baboon Camp” (Beccari Expedition).

762. PREPONA LAERTES IKARIOS.

P. laertes ikarios, Fruhstorfer, “ Insektenborde”, 1904, p. 126.

In the Tring Museum from Demerara.

763. Prepona demodice.

Nymphalis demodice, Godart, Enc. Meth. TX, p. 408, n. 193 (1823),
Berbice (W. E. Augustus). (Coll. Ent. Div.).

764. Agrus narcissus.

A. narcissus, Standinger, Ex. Tagf. I, p. 165, t 57 (1888).

Oronoque-New River confluence (Major Beddington). This is the first
record of this splendid species from British Guiana.

Family ERYCINIDAE.

765. Themone poecila.

T. poecila, Bates, Journ. Linn. Soc. Zool. IX, p. 378 (1868).
Oronoque-New River confluence < Major Beddington).

766. Tmetoglene colaxes guianensis.

T. colaxee guianensis subsp. nov.

Description. Fore wings less pointed than in typical T. Colaxes Hew. from
Ecuador, the subapical band. of white spots followed by an additional small spot
in cellule 2; marginal black band of hind wings only about half as wide.
Oronoque-New River confluence (Major Beddington). Type in the British
Museum,

'767. Symmachia accusatrix.

8. cuscvsatrix, Westwood, Gen. Diurn. Lep. p. 445, n. 3, note (1851).
praZil-British Guiana Boundary (Major Beddington).

CATALOGUE OF THE LEPIDOPTERA RHOPALOCERA OF BRITISH GUIANA. 239

768. NYMPHIDIUM MINUTA.

N. minuta, Druce. Proc. Zool. Soc. 1904, p. 487.

Parika (A. Hall).

A very small species but apparently common.

769. ARICORIS EPITUS.

Papilio epitvs, Cramer, Pap. Ex. Ill, t. 270, C. (1782).

Coverden, Demerara River (A. Hall, March, 1939).

770. Theofe leucanthe.

T. leucanthe, Bates, Journ. Linn. Soc. IX, p. 405 (1868).

Marlissa, Berbice River (Beccari Exped.).

771. Theope thootes.

T. thootes, Hewitson, Ex. Butt. II, Theope t. 1, f. 9, 10 (1860).
Parika.

Family LYCAENIDAE.

772. Thecla gabriela.

Papilio gabriela, Cramer, Pap. Ex. I, t. 6, C.D. (1775).

Berbice (W. E. Augustus). (Coll. Ent. Div.).

773. Thecla philinna.

T. philinna, Hewitson, Descr. Lyc. p. 19, n. 43 (1868).

Parika.

774. Thecla cydia.

T. cydia, Hewitson, 111. Diurn. Lep. p. 160, n. 285, t. 63, f. 433, 434
(1874).

Paradise, Berbice River (Beccari Exped.),

775. Thecla vesulus.

Papilio vesulus, Cramer, Pap. Ex. IV, p. 340, I.K. (1782).

Wismar (A. Hall).

776. Thecla megacles.

Papilio megacles, Cramer, Pap. Ex. IV, t. 333, E.F. (1782).
Rockstone (Beccari Exped.).

776a. ( Thecla calus.

Polyommatus calus, Godart, Enc. Moth. IX, p..640, n. 83 (1823).
Parika (A. Hall, March 1939).

777. Thecla polibetes.

Papilio polibetes, Cramer, Pap. Ex, IV, t. 341, B.C. (1782).

Parika.

tX, 4,

240 AGRICULTURAL JOURNAL OF BRITISH GUIANA.

778. THECLA ARUMA.

T. aruma, Hewitson, 111. Diurn, Lep. p. 192, n. 878, t. 76, f. 609,
610 (1877).

Carimang River; Mt, Roraima,

779. THECLA ANTHORA,

T . anthora, Hewitson, 111. Diurn. Lep. p, 191, n. 373, t. 76, f. 604,
605, 606 (1877).

Kumpukari, Demerara River (Beccari Expect.),

Family HESPET1IDAE

Sub-family PYRRHOPIGINAE

780. Pyrrhopyge proculus.

P. proculus, Hopffer, Stett. Ent. Zeit 1874, p 370, n. 3.

Coverden, Demerara River (A, Hall); New River (G. A. Hudson).

781. Pyrrhopyge kileyi guianae,

P. rtleyi guianae, Bell, Ent. News XLII, p 68 (1932).

Parika (A, Hall).

782. JEMADIA FALLAX.

J. fallax, Mabille, Ann. Ent. Soc. Belg. XXI, p. 22.

New River (G. A. Hudson).

Sub-family HESPERIINAE.

783. Phocides distans.

Erycides distans, Herrich-Schaeffer, Prodr. Syst. Lep. Ill, p. 60, n. 4
(1869).

Great Falls (Beccan Exped.).

784. Heteropia IMALENA.

Telegonus imalena, Butler, Lep. Ex. p. 109, t. 40, f. 1 (1872)
Demerara River (Beccari Exped.).

785. Chrysoflectrum perriciosum.

Eudamvs perriciosus, Herrich-Schaeffer, Prodr. Syst. Lep III, p. 65
n. 18 (1869).

Coverden, Demerara River (A. Hall).

Always a rare species.

786. Bungalotis ramusis.

Papilla ramusis, Cramer, Pap. Ex. IV, t. 842, C (1782).

Jftsproro. N.W. District (L, p. Cleare) ; flew River (G. A. Hudson),

CATALOGUE OP THE LEPIDOPTERA RHOPALOCERA OF BRITISH GUIANA. 241

787. Nascus euribates.

Papilio euribates, Cramer, Pap. Ex. IV, t. 393, D (1782).
Oronoque-New River confluence (Major Beddington).

788. Paradros alcmon.

Papilio alcmon, Criftner, Pap. Ex. Ill, t. 261, D.E. (1782).

Mariissa, Berbice River (Beccari Exped).

789. Paradros dumerili.

Hesperia dunteril, Latreille, Enc. Moth. IX, p. 757, n. Bo (1823).
Oronoque River (Major Beddington).

790. GARGA PLATON.

Conognathus plat on, Felder, Wien. Ent. Mon. VI, p. 181, n. 163 (1862).
New River (G. A. Hudson).

791. Pythonides lernia.

Leucochitonea lernia, Hewitson, Descr. Ilesp. p. 48, n. 6 (1868).

New River (G. A. Hudson).

792. Pythonides lugubris.

Leucochitonea lugubris, Felder, VeWi. Zool. Bot. Gee. 1869, p. 476, n. 32.
Parika; Kaietcur Falls.

793. Pellioia bessus.

P. bessus, Moschler, Verh. Zool. Bot. Ges. Wien XXV, p. 341, t. 4, f. 25
(1876).

Parika; Mabaruma.

794. Eudamidas ozema.

Achluodes ozema, Butler, Trans. Ent. Soo. 1870, p. 515.

Kurupukari, Demerara River (Beccari Exped.).

795. Ebrietas undulatus.

Nisouiades undulatus, Herrich-Schaeffer, Corresp. Blatt. Regensb.
XVIII, p. 171 (1864).

Demerara River, Parika.

796. Miltomiges verticalis.

M. verticalis, Plotz. Exot. Schmett. Ilesp. XX, p. 1478.

Coverden, Demerara River (A. Hall).

Xhis rare species probably belongs to some other genus.

Sub-family PAMPHILINAE.

797. COPAEOIDES MINIMA.

C. minima, Edwards, Trans. Am. Ent. Soc. Ill, p. 196 (1870).
Kaieteur Savannah (Smart & Richards),

242 ' AGRICULTURAL JOURNAL (V BRITISH GUIANA. {X 4.

798. Phenes Cornelius.

Hesperia Cornelius, Latreille, Enc. Meth. IX, p. 764, n* 104 (1828),
Parika; Coverden.

799. Cydrus naevolus,

C. naevolus, Godman & Salvin, Biol. Cent* Am. Shop. II, p. 518, t. 96,
f. 19-21, (1900).

Parika (A. Hall).

800. Euroto compta.

Pamphila compta, Butler, Trans. Ent. Soc. 1877, p. 152.

Parika; Coverden.

801. Euroto geisa.

Pamphila geisa, Moschler, Verh. Zool. Bot. Ges Wien. 1878, p. 216.
Pafika; Coverden.

This species appears to be quite distinct from E. compta, not synonym as
given m Seitz.

802. "Lerema peneia.

L. peneia, Godman & Salvin, Biol. Cent. Am. Rhop. II, p. 655, t. 99,

f 48, 49 (1900).

Parika.

803. Mnasilus pencillatus.

M. pencillatus, Godman & Salvin, Biol. Cent. Am. Rhop. II, p. 570,
t. 100, f. 39-42 (1900).

Bartica.

804. Vehilius schbria.

H. scheria, Plotz. Exot. Schmett. XX, Heap. t. 1475.

Coverden, Demerara River.

805. Megistias tripunctus.

Cobalus tripunctus, Herrich-Schaeffer, Corresp. Blatt. Regensb. XIX,
p. 53 (1865).

Mt. Roraima; Coverden.

806. Megistias isus.

M. isus, Godman & Salvin, Biol Cent. Am. Rhop. II, p. 574, t. 101,
f. 9-11 (1900).

Quonga.

807. Zenis dissoluta.

Cobalus dissoluta, Herrich-Schaeffer, Prodr. SyBt. Lett. Ill, t> 78.
tt. 7 (1889). *

farika.

CATALOGUE Of THE LBPIDOPlEfcA RJtOPALOCERA OF BRITISH GUIANA. 243

808. CYMAENES siliub.

Hesperia tIUus, Latreille, Enc. M?th. IX, p. 764, n. 103 (1823).
Qttonga; Parika.

809. MNASEAS BICOLOfc.

M. bicolor, Mabille, La Naturaliste, 1889, p. 174.

Parika; Mabaruma.

810. Callimormus vetula.

C. vetula, Mabille, La Naturaliste, 1888, p. 173.

Bartica; Coverden; Kaieteur Falls.

811. Callimormus diaeses.

C. diaeses, Schaus. Proc. U.S. Nat. Mus. 1902, p. 456.

Cov^den ; Parika; Quonga.

81F Themeston maroma.

Carystus maroma, Miischler, Verh. Zool. Bot. Ges. Wien, XXVI,
p. 380 (1876).

Mackenzie (Beccari Exped.).

813. THRACmES ANTONINUS.

Hesperia antoninus, Latreille, Enc. M?th. IX, p. 746, n. 47 (1823).
Parika; Coverden.

This species appears from the genitalia to be distinct from T. salius, Cl*am.
to which, however, it is very similar.

CORRECTIONS.

Page 33. n. 63. In place of Euptychia batesii read E. harpyia, Felder,
Reise Nov. Lep. Ill p. 482, n. 832 (1867).

Page 37. for Heliconiinea read Helicovwme.
page 97. n. 155 for Eunica moninia read E. monima.

244

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

IX 4.

INDEX.

▲

abaris

Amarynthis

156 amathea

... 154
... 96

acanthoides

....

154 amazona ....

... 98

accusatrix ....

....

238 amazonica ....

... 153

acesta

....

98 amelia

... 96

acherois ....

157 Amenis

.... 216

acheronta ....

....

101 amesis

.... 150

achilles

37 amphinome

.... 99

Achlyodes ....

....

224 amphion ....

.... 219

Acolastus ....

218 amphione ....

.... 167'

acontius ....

97 amra

.... 216

ACRAEINAE

....

37 amyclas ....

.... 216

Actinote ....

37 amyntas ....

.... 218

actor ion ....

....

35 anaea

.... 102

actoris

150 anaphus ....

.... 219

Adelpha ....

....

100 Anartia ....

.... 96

adjunctus ....

235 anastomosis

. .. 223

adonis

37 Anastrus ....

...., 223

adoxa

220 Anatole ....

.... 153

adulta ' ....

29 anchises ....

.... 168

aecas

233 anchisiades

.... 169

aede

39 Ancyloxypha

.... 226

aegle

30 Ancylurus

.... 151

aegrota

236 androgeus

.... 169

aemulius ....

....

156 andromeda

.... 32

aeneas

....

168 anius

.... 154

aeolia

152 anna

.... 97

Aeria

31 annulifera

.... 156

aerope

....

152 anteas

.... 37

aethra

....

229 Anteros . ..

.... 153

agathina v ...

101 anthora

.... 240

agave

.. ..

166 anthracinus

.... 229

Ageronia ....

....

98 Antigonus

.... 224

agesilaus ....

....

216 antimache

.... 101

Agrias

102, 238 antinoe ....

.... 237

agyrtus ....

150 antiochus ....

.... 39

alardus

219 Antirrhaea

.... 31

albimargo ....

218 antonlnus

.... 243

albula

166 AntonOe ....

... 236

alcmon

241 apastus

.... 219

Alesa

150 Apaustus ....

.... 226

Alexirrhoe

29 Appias

.... 165

aliphera ....

40 Aprotopoa

.... 29

almoda

230 araeoatolya

.... 149

alus

229 arbas

.... 146

arcalaus ....

.... 228

areas

.... 169

archippus

.... 28

Archonias

.... 1Q5

arcius

.... 151

argante Catops.

.... 166

argante Eupt.

.... 34

argus

.... 229

argyrodines

.... 154

argyrogramma

.... 153

ariarathes

.... 215

Aricoris ....

159, 239

Arinome ....

.... 99

aristas

156

arnaea

.... ' 34

aroma

- 235

arsalte

..... 226

artemides ......

... 223

Artines

..... 234

artona

_ 232

aruma

..... 240

asema

.... 230

asine

.... 218

assecla

... 222

astarte

..... 98

astrea

.... 31

astrigera —

„.. 222

astydamia ......

.... 39

astyoche —

..... 31

asychis

.... 225

Ate

.„ 222

athemon ....

.... 97

athenion

.... 226

athymbra ......

.... 164

atizies

...... 234

atrius

.... 163

Atrytone —

22')

aulestes ancyl.

„.. 151

aulestes Thym

. ..... 219

aunus

220

Autochton —

.... 219

autosilaus —

..... 216

aveyrona

... 41

axiothus ......

..... 154

azanoides —

157

azines

... 219

baeotia

...... 157

Baeotis

158

baeotus

..... 102

barii

...... 29

basilea

103

batesii Eupt.

..... 33

batesii nessaea

...... 97

batesii Theda

160

batesii Zeonia

...... 151

beccarii

.... 237

bellona

..... 165

beltiana

..... 150

belus

..... 169

beorj

..... 163

berecyntllia

...... 35

beaBus __

241

»•••< MMM

...... 35

biblis

bicolor

...... 243

binocula —

.MM. 33

bistrigula —

...... 229

bomilcar —

152

BRASSOLIDAE

35, 237

Brassolis

...... 35

brephos

165

brevimaculata

...... 40

brino —

...... 228

briscius

...... 236

Brontiades

...... 226

Bungalotis

220, 240

buniae

..... 165

buphonia —

164

burneyi

...... 39

busirus —

...... 224

caburi

...... 169

cachrus

..... 158

caepio mmm

220

Caerois

..... 32

oaer,ulea —

..... 237

caesaries m..m

_. 164

caeso

228

cafusa —

..... 104

calchas

,™ 220

calchinia —

.... 164

Cahgo »*mm

INDEX.

Callicore

..... 98

Callimormus

234, 243

Calliope

.... 158

Callitaera

..... 31

Callithea

— 98

Callithomia

.... 29

Callizona

...... 98

Calloleria .m.m

...... 30

calus

..... 239

calvina

.... 233

calyce

...... 158

camariensis

.._ 30

Camptopleura

..... 225

cana

....m 99

cannae

mm.. 229

capaneus

M.... 148

cardui

..... 96

caricae

...m. 157

carima

.... 223

carinenta

mm.. 103

carthesis ....

.... 167

Caryestoides

.... 234

Carystus '....

232, 243

cassiae

.... 35

cassina

.... 35

cassiope

.... 237

cassius

.... 160

Catagramma

98, 238

cathaea

.... 234

catillus

.... 217

Catoblepia

.... 35

Catonephele

97, 237

Catopsilia

.... 166

cauter

.... 162

cayana

...... 30

cecilia

.... 147

Cecrops

.... 219

Cecropterus

219

Celaenorrhinus

.... 222

celia

.... 32

celmus

.... 164

cephus

.... 34

ceramina

....' 219

cerata

.... 164

Oratinia

...... 29

cerealis

.... 155

ceres

.... 28

cerialis

245

222

chalestra

228

Charidia

225

Charis

154

cheles

146

Chiomara

225

chiomara

235

chiron

Ghlorippe

101

chloris

Chlosyne

chorinaeus

Chyrosoplectrum

240

chyrsus .mm.

153

eingulicornis

152

cingulus

152

cippus

148

claudia

102

clavus

234

cleanthes

236

clearei

cleonus

154

clio

clorimene

237

cluena

dymena

clysonymus

237

clytemnestra

103

clytia

Cobalopsis

329

Cobalus

229

cocala

100

Coea

101

coea

148

coeleste

222

Coeliades

233

coelus

218

Cogia

220

Colaenis

colaxes

238

color

162

columbaria

230

columbicola

162

comosa * ....

159

compta

242

confusa

connexa *

Cocognathus

....

241

contubernalis

....

222

Copae&des

241

coradea

• ••#

284

coral ii

• •••

Cornelius ....

242

corbulo

228

coridon

....

288

crameri

• •••

crassus ....

189

Cremna ....

....

180

creteus

• • 4 •

219

Cricosoma

....

152

crinisus

«...

221

crisis

167

crolus

....

168

crotopus

......

104

cupido

....

147

Cyclogvpha

•••f

225

Cyclosaemia

....

223

cydia

....

239

Cydrus

....

242

cyllarus

....

163

Cymaenes ....

283, 248

cynea

......

228

cynisca

....

234

cynosura ....

....

Cyrenia ....

....

151

cyrianassa

......

Cystineura

......

cytherea ....

....

101

daira

....

166

dalmani

......

228

Damns

234

DANAIDAE

DAN AIN AE

......

Danais ......

IHH ,

Daptonoura

mmm

165

dardus

147

darius —

MM*

decitna ...«.

Mini

decinea —

235

decora

ttm ,

232

%«idamia —

dalila

delphicola —

100

demodice __

„„„

238

demophite

165

demophon _

M.M.

101

dexamenes

102

diaeses

„„„

243

dictys hhh

-#M ,

231

didia

223

dido

Didonis

didymaon mm

MIM ,

161

dilutata

Dion

238

Dione

Diopthalma

MM „

149

Diorhina

......

151

Diphoridaa

225

dirce

Dircenna

......

Dismorphia

167

dissoluta

......

242

distans

240

dolicaon

216

dolylas

161

dorantes

.m.<

217

dorilas

......

151

doris

...m

doryasa

..m.

164

doryssus

218

dracontis

draudti

216

drusilla

mM.

165

dryope

dubius

m*N

233

dumerili

„„„

241

duvalii

m...

159

Dynamine

Dynastor

...m

dyscritus

M.m

229

Dysmathia

158

Eantis

224

ebenus

225

Ebrietas

.wm

241

Echelatus

224

echemon

168

Echenais —

155

echion —

163

echo

ecliptica

285

Eetima

99,

288

Ectomis

Mm*

220

edata

„„„

284

edda —

280

egeria

Mm.

egina Meg.

288

egina Mel.

elathea

166

Elrietas

225

Emesis

154

emilia

emylius

*"* M

155

endymion

447

enotrus

119

Entheus

Jhfti

eous

epaphus ......

Epeus

.«m

221,

epictetus

mrn

227

Episcada —

MmM

epitus

289

epulus

155

erato

M .m

erebina

229

erema

163

eresimus

Mm.

ergeteles

MMM

168

ergina

.mM

162

eribotes ...m

MMM

102

erictho m«.»

erotia

MmM

100

Erycides

MMM

240

ERYCINIDAE

103,

288

ERYCININAE

MMM

147

Eryphanis

.Mm

eryx

MMM

160

Esthemopsis

M.m

152

ethilla mm

euboea «m.

MMM

146

eubotes

MM M

145

eubule mm

166

eucharila

MMM

150

eucoma mm

eucritus ^

•MM

145

Eudatnidas

224. 341

Eudamus ^

217

INDSOf.

247

eudocia

N|fft

159

floralis

......

150

Eueides _

•MM.

florula

MMM

eugeon

■ tir --

146

foliorum

......

159

eulalia _

m „ r

fontus

Mm..

eulogius

formosus

......

153

eulione —

u „„

145

foyi

......

164

eumeus

M , Mt

152

fridericus —

......

224

eumelus

MWM

222

fulgerator

......

218

eumene

148

fuliginosa —

......

231

Euaica —

96, 237

fulminans

......

157

eunice

mMt

furina

.M.M

237

Eunogyra

mmm

150

euoras _

146

U-J IJJPM

146

Kf r m

lrr ., T

gabriela

MMM

239

Hr if am

33, 236

ganymedes

M..M

160

220

garata

...M*

216

wM PP> nas.

rtl ,. r

241

Garga

241

dWkShus

•*««

geisa

..MM

242

gela

156

feuroUt

237, 242

gelanor

MM..

146

eurgas

gentius

221

Eurybia

147

gera

M.m.

236

•ttrycles

HM|(

217

gladolis

• MM.

226

^pffypus

146

glauce

...M.

102

Efuselasia

104

glaucolaus

M.M.

215

EUSELASIINAE

104

glycon

•M...

eustachius

104

Gonepteryx

M..M

167

euterpe

158

Goniurus

MM..

217

Eutychide —

230

Gorgythion

MMM

225

eutychus —

104

gracilis

226

evadnes —

.....

227

gradatus

•M.M

excelsior

238

gratiosa m.m.

166

exornata —

Grynopsis

222

guianis

M..M

guianensis

238

gulnare

MMM

fakrina

mmm

163

gyas

.M.M

154

faHax

„mm

240

Gynaecia

MMM

faonia

MM*.

155

faunus _

.MM.

151

februa —

^eroxiia »»»■

Haematera

......

ferrago —

H4MM

227

Haetera «..m

MMM

fftata —

284

haJiemede u..„

MMM

147

flscheri —

hmh

235

Hamearis

MMM

155

Flacilla

233

hanno

.MM.

160

flavesoene

mmm

hannonia —

MMM

heberia

™ 226

hebrus nM .

— 158

hecale mm..

— 38

hecuba —

— 36

hegesia

.~. 41

Helias

..„ 225

heliconides

...... 150

HELICONIINEA 37, 237

Heliconius

38, 237

Helicopis

147

helie

...... 102

Helioptes

.... 226

hemes —

_ 224

Wemiargus

160

hemon —

161

herennius

223

hermes

...... 34

hero

..... 223

herse

hesione

....* 33

Hesperia ....

.... 216

HESPERIDAE

216, 240

HESPERIINAE 217, 240

hesperitis ....

.... 163

Hesperocharis

.... 165

hetaerius ,...

.... 215

Heteropia ....

.... 240

hewitsonii

.... 35

hippea

.... 153

hippona ....

.... 103

Hirsutis ....

.... 28

hisbon

.... 158

Historis . ..

.... 101

hiibneri Ecfaen.

.... 156

hubneri Helie.

.... 39

Hyalothyrus

.... 221

hydara

.... 40

Hydraenomia

.... 220

hygia

.... 29

Hylephila ....

.... 226

hypargyra

.... 282

hyphaea ....

.... 149

Hyphilaria

.... 149

Hypn^

.... m

Hypolimnas

.... 100

hydoxantha

.... 159

hyppason ....

.... 169

248

AGRICULTURAL JOURNAL OP BRITISH GUIANA,

IX, 4,

ibycus

14b

idas Cat

idas Prot. —

218

idomeneus

ikarios

238

ilioiieus

illuciens — «««

231

imalena

240

imperialis

160

ina

233

inachia

infernalis Agr

102

infernalis Mion

221

ingae

162

integra

231

invirae

iona

iphias

149

iphiclus

101

irenaea

158

irrorata

152

isabella

Isapis

150

isidora

103

isus

242

Itaballia

165

ITHOMIINAE ......

Ithomiola

150

itonis

237

itylus

219

Kayei

labdacus ....

lacinia

laertes

lafresnayi

lagia

lagus

lamia Eur.
lamia OPier.
lamia Nymph,
lamia Per.
lampeto
laothoe
larua

lateritia ....
laurea
lavinia
lea

Lemoniaa ....
lena
lenea
leonida
leprieurii ....
Leptotes ....
Lerema
lernia

leucanthe ....

leucas

leuce

Leucidia ....

.... 100

.... 146
.... 96

.... 238
.... 233
.... 222
.... 169

.... 147
.... 31

.... 157
.... 97

.... 40

.... 97

.... 32

.... 153

.... ^33

.... 34

.... 155
.... 31

.... 30

.... 102
. .. 98

.... 160
231, 242

linus

liria

liriope

lisioa

lisimon

lisus

liiana

litteia

longirostris

lucaria

lucianus ......

lucinda

liicius

lucullea

ludena "

lugubris ......

lybia — '

LYCAENIDAE

lyeaenina

lycinnia

Lyeorea

lydia Eupt.

Jydia Ter

Lymnas ......

Lynceates ....

lyaander ......

lyaippua

C^\40

m saa
m

macareus ,
machaera ,
maera
magete
magnifica
malvina ,

Leucochitonea 222, 241 mandana ...... ..... 154

japetus 102 leueocyana .... 166 mango 232

jarbas 151 leucone 233 mantus .... 157

jatrophae 96 Jsucopogon ..... 231 Marela ..... ..... 221

Jemadia 240 Leucothyris .... 30 Maroma 243

jesia 236 libye 34 marshalli 221

jolus 232 Libythea 103 marsyas — 161

jovianus 223 licinia Dism 167 marthesia .... 103

julia 41 licinia Eus. 104 martia 161

juno 41 Ugynyostola 221 matho — 164

jjustinanus .... 280 limbia 166 mayors 161

juvenis 225 lindeni 147 meander _. ™. 101

javentus a. 284 lindora ^ 217 Mechanics — 29

INDEX.

249

mediatrix .
Megacles .
megalops .
Megalura
Megistanis
Megistias

melaene

melander Eud.
mclander Lymn.
melanotica
melaphaea

Melinaea

melius
melons
' imeiife

— 28 Mnaseas —

239 Mnasatcas

..... 229 mnasias —

99, 237 Mnasilus

102 Mnasitheus

232, 242 mneme

148 Mnestheus

224' modesta

151 moles
99 mollina
104 Molo
28 mol ops
229 molpe

101 mcninia

39 monu8te

158 moereana

158 morena

222 MORPHIDAE
37 Morpho
154 morvus

243

231

242

231
28
234

236

232
216
157

165

231

102

103

nina 148

mse ..... .. .. 30

Nisoniades 223, 241

nitocris 221

nivepunctata 162

ncbilis 160

nola 152

nomia 155

Notheme 152

numala 38

numen 161

numilia 97

nyctelius 227

nymphaea 165

NYMPHALIDAE 37, 237
NYMPHALINAE

40, 237

Nymphidium 156, 239

tnerwtriesii

.... 232

munditia

.... 162

obrinus —

menoetes

..... 148

mutilla

..... 29

obscurus .....

_. 223

Metmeria —

...... 32

mylitta

..... 98

ochrstaeniata

~ 37

menes

..... 215

myncea

ocola

.... 227

* menippe

.... 167

myrinna ......

..... 96

ocypete

..... 33

merianae

.... 35

mys Eup

104

cdilia

.... 103

Mesene

..... 152

mys Zar

..... 227

odius

101

Mesentina

..... 100

Mysoria

..... 216

oileuws

...... 36

Mescsemia

..... 147

omphale

... 102

Metacharis

.... 155

oniap

.... 97

Metamorpha

...... 40

naevolus

...... 242

Onophas

..... 230

meteJlus

...... 36

Napaea

_.. 150

Opsiphanes

.... 35

methion —

.... 149

Napeogenes

orchamus —

.~ 228

Methionopsis

..... 233

Narcissus —

.... 238

orcinus

.... 220

Methonella

147

Nascus

220, 241

oreas

..... 149

metope

.... 148 •

nauplia

.... 41

orestes -

.... 156

midas

.... 220

neaerea

.... 99

orf it?

..... 104

Milanion —

...... 224

nearchus ....

. 22^

orion

... 218

Millomiges

.„. 241

nebulosa

..... 236

ornata

.... 32

milvius

..... 227

neis ......

..... 219

crnatrix

..... 160

Mimocastnia

..... 150

neophilus ......

..... 168

orpheus

... 150

Minima

.... 241

nero

.... 228

orphise

minos

.... 233

Nessaea —

... 97

orsedice —

„. 149

minuta

.... 239

Newtoni

.... 236

Orses

— 234

Mionectes

_.. 221

nicaeus

.... 147

orsiloihus

... 100

misippus ......

.... 100

nicias

..... 149

Ourocnemis

„„ 154

mithras —

_ 168

Niconiades

..... 228

ovidius

154

mithrax —

„. 225

nigrofulva

Ozema

— 241

252

AGRICULTURAL JOURNAL OP BRITISH GUIANA.

[X, 4.

tiberius ....

Timetes ....

Timochares

tinea

tiphys

tisias

tizona

Tmetoglene

tolumnia ....

torquatus ....

torqueor ....

tricolor

trifascia ta

Trioedusa

triopas

tripunctatus

tripunctus

trite

troehila

tullius'

tumatumari

tryhana .!..

tryxus

tytia

ubia

undulatus
uniformis
Urbanus ....
urites

.... 280 utica
.... 238 uzita
.... 224

223 Vacerra
225 va l en tina
1Q0 vanillae
238 Vehilius

34 veleda

169 venezue l ae

164 venilia
34 venulius

224 vemusta
227 verticalis
4gg vertumnus

232 vesu l us
242 Vettius

I 166 vetula

jgg vetus
449 vetustus
gg vibex
227 vibilia
224 Victorina
45g viculata
vigor us
Vila
viola

. .. 151 violetta
. .. 241 virbius
.... 231 viresca
.... 224 virescens
.... 147 virgilia

104

vitreus

.... 221

104

volupia

.... 165

Vorates ....

.... 232

228

wallacei ....

.... 39

242

wana

.... 31

234

216

xanthaphes

.... 228

153

xanthocles

.... 39

161

xanthus ...

166

xenana

241

xeneta

168

xeniades \ ...

239

xenophanes

233

* »

243

224

Yanguna ....

U, 217

226

Zama

.... 154

Zarepha ....

J ' 80

100

Zaretes

.... 103

Zariaspes ....

.... 227!

227

Zeanger ....

... *55

Zeleucus . ..

. .. 216

Zena

.... 104

153

Zenis

233, 242

Zeonia

.... 151

161

zephyritis

.... 158

218

Zerua

.... 155

zygia * ....

.... 157

NOTE*

MINUTES OF THE SEVENTEENTH MEETING- OF THE
ADVISORY BOARD OF AGRICULTURE

HELD AT THE OFFICE OF THE DEPARTMENT OF AGRICULTURE
ON WEDNESDAY, AUGUST 16, 1939, AT 1.30 O’CLOCK P.M.

Present.

Thfc Director of Agriculture

TlMjjsDeputy Director of Agriculture (ag. ) ...
. Son. R. E. Brassington
J. W. Jackson
i E. M. Walcott
Jjffr, S. Andries

with

\lapt. J, F. Irving, M.C.

Absent.

* Hon. Peer Bacchus
Mr. W. H. Richards.

Chairman

Members

Secretary

An excuse for non-attendance was tendered by Mr. W. H. Richards
who had to be present elsewhere at another Government meeting at the
same hour. The Chairman observed that it was becoming increasingly
difficult to find convenient days for most meetings.

Minnies, The minutes of the last meeting held on January 25 which
had previously been circulated were confirmed. The Chairman referred to
the following matters relating thereto :

(1) Betbiee Exhibition. The Chairman stated that the Agricultural Exhi-
bition staged at New Amsterdam could be considered highly satisfactory having
regard to the adverse weather conditions. T t was estimated that 5,000
persons were present. The total receipts, comprising an allocation of $500
from the Department’s grant-in-aid vote, gate receipts, contributions from
the Sugar Producers’ Association, the Rice Marketing Board and the Berbice
Agricultural Committee, amounted to $937.58 as against an expenditure of
$1,274.34, leaving a deficit of $336.70 which would be met by a further
allocation from the grant-in-aid vote, field competitions having been cancelled
to permit of this. The expenditure was higher than was anticipated due
to the heavy rains and the consequent additional expense involved in keeping
the grounds free of water, purchase of shell for the paths, and the necessity
* for the hire of galvanised sheets and duck-boards for the stands.

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 4.

252 ,

tiberius

....

230

Timetes ♦...

238

Timochares

224

tinea

....

155

tiphys

....

223

tisias

....

225

tizona

100

Tmetoglene

238

tolumnia ....

....

torquatus ....

169

torqueor ....

....

164

tricolor

....

trifasciata

224

Trioedusa

227

triopas

168

tripunctatus

232

tripunctus

242

trite

166

trochila

. ..

153

tullius'

149

tumatumari

....

tryhana

227

try xus

....

224

tytia

156

ubia

. . .

151

undulatus

241

uniformis

....

231

Urbanus ....

....

224

urites

....

147

utica

.... 104

uzita

.... 104

Vacerra ....

.... 228

valentina ....

.... 83

vanillae

.... 41

Vehilius ....

231, 242

veleda

.... 234

venezuelae

.... 216

venilia

.... 153

venulius ....

.... 161

vemusta ....

.... 166

verticals ....

.... 241

vertumnus

.... 168

vesulus

.... 239

Vettius

.... 233

vetula

.... 243

vetus

.... 224

vetustus ....

.... 38

vibex

.... 226

vibilia

.... 40

Victorina ....

.... 100

viculata

... 40

vigorus

... 227

Vila

.... 99

viola

... 96

violetta

.... 153

virbius

viresea

. .. 161

virescens ....

.... 218

virgilia

.... 32

vitreus

221

volupia

165

Vorates

232

wallacei

wana

... .... 31

xanthaphes

.... 228

xanthocles

.... 39

xanthus

... '\... , 35

xenana

xeneta
xeniades \ .

|J$L

Xenophanes

Yanguna .

... W 217

Zama

‘ 154

Zarepha

- SO

Zaretes

108

Zariaspes .

327

Zeanger

.. 188

Zeleucus .

216

Zena

104

Zenis

233, 242

Zeonia

151

zephyritis

... 158

Zerua

155

zygia

157

NOTE.

MINUTES OF THE SEVENTEENTH MEETING OF THE
ADVISORY BOARD OF AGIUCULTURE
HELD AT THE OFFICE OF THE DEPARTMENT OF AGRICULTURE
ON WEDNESDAY, AUGUST 16, 1939, AT 1.30 O’CLOCK P.M.

Present.

1 The Director of Agriculture

$lljS|jDeputy Director of Agriculture (ag.) ...
Hon. R. E. Brassington
a J. W. Jackson
^ E. M. Walcott
|lr. S. Andries

with

’Capt. J. F. Irving M.C.

Absent.

Chahman

Members

Secretary

Hon. Peer Bacchus
Mr. W. H. Richards.

' An excuse for non-attendance was tendered by Mr. W. H. Richards
who had to be present elsewhere at another Government meeting at the
same hour. The Chaiiman observed that it was becoming increasingly
difficult to find convenient days for most meetings.

Minutes. The minutes of the last meeting held on January 25 which
had previously been circulated were confirmed. The Chairman referred to
the following matters relating thereto :

(1) Be) bice Exhibition. The Chairman stated that the Agricultural Exhi-
bition staged at New Amsterdam could be considered highly satisfactory having
regard to the adverse weather conditions. T t was estimated that 5,000
persons were present. The total receipts, comprising an allocation of $500
from the Department's grant-in-aid vote, gate receipts, contributions from
the Sugar Producers' Association, the Rice Marketing Board and the Berbice
Agricultural Committee, amounted to $937.58 as against an expenditure of
$1,274.34, leaving a deficit of $330.76 which would be met by a further
allocation from the grant-in-aid vote, field competitions having been cancelled
to permit of this. The expenditure was higher than was anticipated due
to the heavy rains and the consequent additional expense involved in keeping
the grounds free of water, purchase of shell for the paths, and the necessity
‘ for the hire of galvanised sheets and duck-boards for the stands.

254

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

[X, 4.

(2) Banana Experiments. As previously recommended by the Board,
the 5-acre banana block at Plantation Middlesex had been abandoned and
cassava trials had been laid down there instead. At Supply the bananas t
despite regular attention to cultivation, etc., were growing very poorly.
Cercospora leaf spot was still present, though it had not been so bad this
year owing to drier weather. Panama disease was increasing. As a com-
mercial proposition this plot must also be regarded as a failure.

(3) Rice Mill Engineer. The Chairman stated that as members were
no doubt aware, the Report on Rice Milling in British Guiana
Parker and the Essequibo Coast Rice Committee Report had bee:

The whole question of a Central Rice Mill had now been thorouj
gated, and estimates in connection therewith forwarded to the
of State.

(41 Tobacco Industry. The Chairman reported the accepta:

Legislative Council, from the Colonial Development Fund, of a
of £3,690 to cover the salary and expenses of a tobacco expert
Bradshaw, a tobacco planter of Nyasaland, hajl been selected, and
in this Colony about October.

Rice Industry. Attention of members was called to an interesting
by the Assistant Plant Breeder on Rice Variety Trials which appear!
the March number of the Agricultural Journal of British Guiana. A
sideration of the present results and those obtained in previous years
led to the following general conclusions :

1. Judged from the yield standpoint only, D 114 is the best of all
varieties available.

2. No well tested long-grained variety as yet offers as a substitute
for Demerara Creole, which had been brought to a high state of
purity by selection.

3. D 99, D 109 and D 110 are heavier yielders than the standard
medium-grained varieties No. 79 and Blue Stick, and are worthy
of commercial consideration.

In addition to existing breeding work the Department was still introducing
for trial here a large number of new varieties from India.

Mr. Walcott stated that the whole question of the Rice Industry was
causing a great deal of anxiety to those concerned as there had been a
distinct tendency to decrease production. This was, he thought, the result
of bad advice given to growers and others by so-called leaders of the
people. It was hoped, however, that a vigorous propaganda which the
Rice Marketing Board proposed to inaugurate shortly would have a good
effect and help to stem this retrograde step, which he regarded with grave
concern.

MINUTES OlF THE SEVENTEENTH MEETING OF THE ADVISORY BOARD. 255

The Chairman said the Department of Agriculture was doing every-
thing possible to encourage growers but there was no denying that the
industry was suffering from internal dissension, which, coupled with a
lower price level, reacted unfavourably on the grower.

Livestock Industry , The Chairman announced the appointment of Mr.
H. A, Fraser as Government Veterinary Surgeon in the place of Major T.
Bone who had recently retired. It was proposed that Mr. Fraser, who had had
considerable experience in animal husbandry, should give this phase of live-
stock work his full attention, and that practical talks on the subject would
first at the Stock Farm, Georgetown, and then extended to
v Uof the Colony.

irman mentioned that another order had been placed in England
Poll bull and a Holstein-Friesian bull. The bulls at La Belle
been well employed, and he was glad to say that a greater
being shown in livestock matters generally all over the Colony.

>ort of livestock to Trinidad was referred to and the number
and eggs being exported noted with interest. A diagram demon-
the growth of the trade, which had been prepared by the Eccfhomist
Berbice Exhibition, was displayed.

k Brassington said he understood that there had been a large increase
number of pigs slaughtered by the local butcheries. It was pointed
bat pig-rearing was proving profitable in connection with the coconut oil
Istry and that there was a good demand for breeding animals from the
Farm.

In regard to poultry, there had been a very large demand for eggs and
birds from the Livestock Division, and in consequence two further pens of
Jarred Rocks had been ordered from Canada.

Pavaw . The Chairman said that he had forwarded to the Imperial
Institute, London, samples of certain papaw products prepared by a local
manufacturer seeking markets for these articles, and he had been informed
by the Institute that it had not been possible to find buyers, as it appeared
that there was no market for such products in the United Kingdom. He
was also informed that there was a large number of proprietary jams,
preserves and other such products on the market at the present time and
it was difficult to interest the public in new lines when so many well
established products were available. If there was any market for such
products it was suggested that it would be more profitable to ship in bulk
for bottling on the other side and thus save freight on bottles.

Split Peas . The Chairman mentioned that in connection with efforts to
increase certain food supplies now imported, +he Department had been
working on the preduction of dhal or split peas. He exhibited a sample
pf such peas made from Pigeon Peas by the Chemist, which was considered

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

rx, 4.

2r>fi

highly satisfactory. The processing was easy now that a method had
been found, but there was still some little difficulty in finding a suitable
home-made apparatus for splitting, the idea being that farmers would grow
and make their own split peas in the first instance instead of buying.

Annual Estimates . The pulls in connection with the 1940 estimates
were not yet available, but the Chairman said there was no great difference
from the 1939 figure; it was proposed, however, to expend more money on
livestock, and this was being largely met by re-adjustment of the existing
sub-heads.

Minor Products Mamets. The Chairman reported
marketing certain local products had been taken up with
Marketing Board but the report received was not at all
following is a summary of the information received.

Libenan Coffee. There was no market for coffee from
the United Kingdom. The export trade opinion was that it was
quality, coarse and bitter in the liquor, and quite unsuitable for
trade. It was thought that the Scandinavian and Baltic countri

offer more favourable outlets for this class of coffee.

Plantain Flour . It was stated that one of the principal firms of
had still on their hands the last consignment of this flour
from British Guiana.

Cassava. Java holds a dominating position for cassava products
is also concerned with this industry but is altogether unable to compete wteh
the Javan products of either cassava or tapioca in the English market, Up#
the Marketing Board feels that there is nothing to encourage the hope thaf«
British Guiana will be able to compete in this market.

Fruit Juices . The question of Fruit Juices was in hand and a report
on the subject of the marketing of East African Passion Fruit Juice had a
bearing on the question of fruit juice production, preservation and marketing.
The whole subject is of such importance to the citrus fruit growers of the
Colonial Empire that the Board proposes to continue its enquiries and to
issue a further report on the various processes of juice concentration.

The meeting then adjourned sine die.

PLANT AND SEEf) EXCHANGE.

For the period ending November 1039.
INTRODUCTIONS,

Name

Economic .

Padi — G varieties

Tobttooo—3
Soya Bean

Yegeti|J|f Seeds Assorted

Quantity.

packet each

M o /. each

3 lb.

] lb. each
1 oz. each
100 gms. each

22 lb. :u oz.
4(» lbs. G oz

Whence Supplied

Division of Plant Exploration
and Inf rod action. Bureau
of Plant Industry, U.S,
Dept, of Agriculture,
Washington, D.C., U.S.A,

Paddy Specialist, Madias Agri-
cultural Department, Coim-
batore, Tndia.

Rice Specialist, Bihar, Sabour,
India

Director of Agriculture, Tri-
chur, India,

Supeiintendent, Botanical Sub-
station, Pusa, Bihar, Tndia

Bureau of Plant Industry,
Dept, of Agr. & Commerce,
Manila, Philippine Is.

Messrs. Peter Henderson A Co..
U.S.A

Messrs Hastings Co„ At-

Jr i

lauta, II S.A.

SpiaadP*'No\v Zealand •

i lb

Messrs. At lee, Burpee & Co.,
Pa , T r .S.A.

bet tdp— Big Boston j

4 oz.

do.

y 1

,, — Greou Mignonette |

^bion Seed- -Red and White

I packet

Ferr> -Morse Seed • Co., Cali-
fornia, IJ S.A.

14 lb. each

Messrs. Hamilton A: Co.,
Teneriffe.

Sweet Corn 1 varieties

1 lb. each

do.

Carina Papaya—- var solo

Ornamental *

1 oz. seeds

("anal Zone Expt. Hardens,
Summit, Canal Zone.

Raphia / rimjem

1 lb.

Agricultural Officer, Njala,
Mano,’ Sierra Leone.

Raphia <j radii*

1 lb.

do.

Aniaophttllea lam ina

j 1 lb.

do.

Petuuia Seeds

j 1 1 packets

Messrs. Richard Diener, Ox-
nard, California, C,S. A

Dahlia Seeds

j 2 packets

Daisy Seeds

1 packet

do.

Hibiscus — Yellow

1 plant

Private Collector.

Oleander Yellow

1 plant

do.

PLANT AND SEED EXCHANG E — (Contd.)

INTRODUCTIONS.

Name

Quantity

Sunflower Seeds

G oz.

Sweet Peas— 18 \arieties 1

1 packet each

„ 7

1 packet each

Ipomea — Hea\enly Blue
„ — Scarlet O’Hara

1 packet

1 packet each

Neantht bell a i

2 oz.

Ornamental Seeds

1 packet

„ Cuttings

, v Plants

2:5

Bougainvillea-

varieties— Nos. 2 and 14

cuttings

,.1 curia macro ntha

1 oz. seeds

- DESPATCHES.

N VME

Quantity

Economic •

Beans -3 \ ariet ies

1 packet each

Ipomoea till area

1 lb. tubers

Soya Beaus AVhite Caracas

1 lb

Cary war nnrijrra

1 plant

JJevca braxtUemi*

3 lb. seed

Passijlora coccinea

1 packet

„ launtolia

„ nitidqL

,, quwlratigularis x

Pineapple — Smooth Cayenne

1 packet

8 suckers

— Sugar Loaf

10 suckers

Whence Supplied

Messrs. Peter Henderson & Co.,
U.S.A.

! Messrs. W. Atlee, Burpee &Co.,
I Pa.. U.S.A.

Destination.

. Messrs. Sutton Sous.

13 D, Russell Street,

1 Calcutta, India. f

! Harvard University, Atkins In-
! stitution of the Arnold.
Arboretum, Cuba.

Bureau of Plant Industry,
Dept, of Agr. & Commerce,
Manila, Philippine Is

Director of Agriculture, Trini-
dad.

Biological Laboratories, Har-
vard University, Mass.,
U.S.A.

East African Agrl. Research
Station, Amani, Tangan-
yika, British East Africa.

do.

Agricultural Superintendent,
St. Lucia.

do.

PLANT AN1) SEED EXCHANGE— (fontd.)

Name

DESPATCHES.

QfANTITY

rtfn

Ornamental

A ('(jimftld, uiartinirettsiH

1 packet seed
1 packet seed
II). seed

*20 lb. seed

12 seeds

6 cuttings >
do.
do

3 doz seeds
10 packets

1H packets

Plants

7 packets

4 packets

7 packets
16 jackets
6 plants

Destination

! Agricultural Superintendent,
j St. Lucia .

I do.

| Botanist, Dept, of Agriculture,
Ceylou.

1 Dr. <t. Stafiel, Director of
I Agriculture, Parimaribo,

| Surinam.

! Director of Agriculture,
j Barbados.

Director of Agriculture,

' Trinidad. •

| Horticulturist, U,S. Dept, of
1 Agriculture, Agrl. Expt.

} Station, Mayaguez, Puerto

lii co.

Dept, of Agriculture, Njala,
Mano, Sierra Leone, British
West Africa.

Dept, of Parks, Division of
Forestry, Los Angelea
California, U.S.A.

! The Horticulturist. Dept, of
Agticulture, Bermuda.

j The Curator, Dept, of Botany,
The University, Stellen-
i bosch, S, Africa
' The Middle Egypt Botanic
Station, El Saff, Egypt.
Private Collectors.

do.

METEOROLOGICAL DATA— JULY— SEPTEMBER, 1939.

Record ing Station s 4 j Rain- I sumbeb of DAYS OF RAIN I *2? I MS"

Mouths.

Botanic Gardens.

3 1 1%
I

3 - 8 *S

9» N

3 * ^5

s §4

July

August

September

15 3

3. 08 0

2.43 1 1

Totals |

15.6!)

Means

...

-..n

Berbice Gardens.

Jnly

16. 88

August

2.1)1

September*

.70

»l

Totals

20.40

22 |

Means

...

Onderneeming.

July

8.:>9

August

,100

1 1

1 i

September

1 3.91

i...|

Totals 1

1 7..>0

Means

... 1

Hosororo,

North West District

July

13.00

August

| 8.94

September

| 0.06

Totals 1

28.00

!5 I

25 j 4.37 83.1 73.6 *jflj,86.1
14 5.78 86.8 76.8 8L^8.7

3 28
... ' 17

3 30

, 86.7 75.Sg
j 88.5 75.7 M
1 80.1 1 75.4 8!

p 78.5

It 77.9

188.1 75.4 81-71

85.51 70.7 78.1 88.9
88.0 70.8 79.4 86.9
88.5 70.9 79.7 83.9

Means

87.3 70.8 79 1 86.6

Decords .naocurate.

INDEX TO VOL. \

1939

ictive ” Alumina in B.G, Sugar-cane Soils . ..
of Agriculture — Seventeenth Meeting of the

r Mctagomstylum mhievse, Towns ) in B.G

s Cultivated at Hosororo, North-West District

Agricultural Exhibition

’ Agriculture — Seventeenth Meeting of the Advisory
Gar den, Georgetown — Recent Introductions into the
E, C. L. C. — “ Acidity and “ Active ” Alumina in B.G. Sugar-
cane Soils ” ....

Biii&rflies of B.G.— Catalogue of the 25—41, 96—104, 146—169,

Cacao Cultivated at Hosororo, North-West District
Cattle Raising in British Guiana — Mineral Deficiency and
Chan-Choong, P. A. — “ Results of Padi Variety Trials, 1938 ”

„ „ „ — “Testing Large Numbers of Rice Varieties

by the Quasi-Fagtorial Method”

Citrus Cultivated at Hosororo, North-West District
„ < „ „ Wauna, North-West District

Cleare, L. D. — “The Amazon Fly ( Metegonigtyhm minense,
Towns.) in B.G.” .. . .... ... ...,

Coconuts Cultivated at Wauna, North West District
Coffee Cultivated at Hosororo, North West District
„ „ „ Wauna, North West District

Page

113—123

244—247

55—77

132—133

3, 49—54
244—247
210—214

113—123

215—252

133
194 — 204
13—20

78—88

125—132

136—137

55—77

138

133

AGRICULTURAL JOURNAL OF BRITISH GUIANA.

iv-

Duthib,

D. W. — “ Acidity and “ Active ” Alumina in B.G. Sugar-

>»

cane Soils ”

— “ Mineral Deficiency and Cattle Raising in British
Guiana ”

— “The Soils of British Guiana, South of the 5th
Parallel, and of the North West District” ....

*113—123

Editorials : —

Food Production Campaign
Food Supplies ....

Rice Development
Self-Sufficiency

Exhibition, Berbice Agricultural

Fish Poison Plants Cultivated at Hosororo, North West District
„ „ „ „ „ Wauna, North West District

Foreshore Vegetation East of Georgetown, the ....

Forte, L. A . — “ Double versus Single Planting of Sugar-cane ”

Giglioli, G. — “ Malaria in B.G., IV & V

Hall, A. — " Catalogue of the Lepidoptera rhopalocera ( Butterflies')

of B.G.” 25—41, 96—104, 146—169, 215—252

Hosororo, North West District — Experimental Cultivations at,

1928—38

.... 124—188

Inspection Service, Plant

107

Jewish International Commission, Visit of

«•••

Lepidoptera rhopalocera (Butterflies) of B.G. —

Catalogue of the' .... .... .... 25 — 41, 96—104, 146 — 169

MalagHh B.t*„ IV & V

Experimental Cultivations in the North West
District, 1928 — 39 ”

— “Recent Introductions into the Botanic Garden,

4—12

124—138

Georgetown ” .... .... .... .... 210

■" The Foreshore Vegetation east of Georgetown” 106 — 107
m minense, Towns* the Amazon Fly in B.G. .... 56 — 77

Data ... 45—46, 110, 170

pst District — Experimental Cultivations in the, 1928 — 38 ....

•lant Inspection Service

’he Foreshore Vegetation east of Georgetown

42—43
124— 13S

107

105—107

Palms Cultivated at Hosororo, North West District
„ „ „ Wauna, North West District

134

188

Plant and Seed Exchange .... .... .... .... 44, 108 — 109,

Rice and other Host Plants — Parasitism of Diatraea saccharaUs in,

* by the Amazon Fly . . .... 72 — 73

„ Varieties — Testing Large Numbers of, by the Quasi-Factorial

Method ..*• .... . .. 78 88

„ Variety Trials, 1938 — Results of .... .... .... .... 18 — 20

Royal Commission, Visit of .... .... .... .... 42

AGRICULTURAL JOURNAL OF BWTISH GUIANA.

Seed and Plant Exchange «*• f <«n 44, 108—109

Soils— Acidity and “Active" Alumina in B.G. Sugar-cane * .... 1J0— 126
„ of British Guiana South of the 5th Parallel, juul of the North
West District

Sugar-cane — Double versus Single Planting of .... .... ..^

„ „ — “ Irrigation— Manurial Trials with Sugar-cane on

Flood- Faltowed Frontland ” .... .... ““*■

„ „ — Results of Repent Experiments with

„ „ — Soils — Acidity and “ Active ” Alumina in B.'Q.*

„ Industry — the Variety and Fertiliser Position of, V

Williams, C. H. B. — “ Double versus Single Planting of Sugar-cane”

„ „ — “ Irrigation Manurial Trials with Sugar-cane

on Flood-Fallowed Frontland ”

„ < „ — “Results of Recent Experiments with Sugar-

. cane” ...

,, ,, — “The Variety and Fertiliser Position of the

Sugar Industry, V ”

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Full text of "The Agriculture Journal Of British Guiana Vol Ix (1938-1939)"

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